Phase II Study of Metformin for Reduction of Obesity-Associated Breast Cancer Risk
Phase: PHASE2
Conditions: Breast Cancer Prevention
Sponsor: University of Arizona

UA Project No. 1300000596 
   Protocol Version 11, 10/4/2016 
i 
Phase II Study of Metformin for Reduction of Obesity-Associated Breast Cancer Risk 
Principal Investigator:  
 
H-H. Sherry Chow, Ph.D.
Research Professor of Medicine 
The University of Arizona Cancer Center 
1515 North Campbell Avenue 
Tucson, AZ 85724 
Telephone (520) 626-3358; Fax (520) 626-5348 
schow@azcc.arizona.edu 
Medical Director/ 
Pavani Chalasani, M.D., MPH 
Co-Investigator: 
Assistant Professor of Medicine 
The University of Arizona Cancer Center 
1515 North Campbell Avenue 
Tucson, AZ 85724 
Telephone (520) 626-7725 
PChalasani@uacc.arizona.edu 
Co-Investigators: 
Cynthia Thomson, Ph.D., R.D. 
Professor of Public Health 
The University of Arizona  
Maria Altbach, Ph.D. 
Associate Professor of Radiology 
The University of Arizona 
Jean-Philippe Galons, Ph.D. 
Associate Professor of Radiology 
The University of Arizona  
Jessica Miller, Ph.D. 
Research Assistant Professor of Nutritional Sciences 
The University of Arizona Cancer Center 
Biostatistician/ 
Denise Roe, Ph.D.  
Co-Investigator: 
Professor of Public Health 
 
The University of Arizona Cancer Center 
Funding Agency: 
Division of Cancer Prevention 
National Cancer Institute 
National Institutes of Health 
Rockville, MD 20892 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
ii 
 
 
SCHEMA  
 
Phase II Study of Metformin for Reduction of Obesity-Associated Breast Cancer Risk  
 
Premenopausal women 
(21– 54 yrs old; Overweight or obese; Metabolic syndrome)  
 
 
Screening 
(Informed consent; Medical History; Anthropometric Measures; Fasting blood; Urine) 
 
 
Baseline Evaluation 
(FWR-MRI; Fasting blood; NAF; Urine; Anthropometric Measures; AFFQ/AAFQ; Breast biopsy (optional))  
 
 
Randomization 
(Metformin or Placebo; 75 per arm) 
 
 
Agent Intervention (12 months (52 ± 4 wks))  
(1 tablet of metformin (850 mg) or placebo daily for the first 4 weeks and  
2 tablets of metformin (850 mg) or placebo daily for the remaining intervention period)  
 
 
Month 3 Visit (13 ± 2 wks) 
(Safety; Compliance; Urine) 
 
 
Month 6 Visit (26 ± 4 wks) 
(FWR-MRI; Fasting blood; NAF; Urine; Anthropometric Measures; Safety; Compliance; Breast biopsy 
(optional))  
 
 
Month 9 Visit (39 ± 2 wks) 
(Safety; Compliance; Urine) 
 
 
Month 12 Visit (52 ± 4 wks) 
(FWR-MRI; Fasting blood; NAF; Urine; Anthropometric Measures; AFFQ/AAFQ) 
 
 
Primary Endpoint: 
• 
Changes in breast density assessed by FWR-MRI 
 
Secondary Endpoints: 
• 
Modulation of systemic hormones, growth factors, and cytokines (insulin, sex steroid hormone, IGF-axis, 
adipokines) and anthropometric measures 
• 
Modulation of metabolomic profiles in NAF and plasma and correlations of metabolomic profiles with 
markers of breast cancer risk 
 
Exploratory Endpoints: 
• 
Tissue morphological changes 
• 
Modulation of cellular and molecular targets of metformin in the breast tissue 
 
Abbreviations used in schema: FWR-MRI: MRI-acquired fat-to-water ratio; NAF: nipple aspirate fluid; AFFQ: Arizona 
Food Frequency Questionnaire; AAFQ: Arizona Activity Frequency Questionnaire; IGF: insulin-like growth factor 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
iii 
 
 
 
TABLE OF CONTENTS 
 
 
Page 
COVER PAGE ......................................................................................................................................... i 
SCHEMA ................................................................................................................................................ iii 
 
1. OBJECTIVES ................................................................................................................................... 1  
 
2. BACKGROUND ................................................................................................................................ 1 
2.1 
Significance .......................................................................................................................... 1 
2.2 
Study Design and Rationale ................................................................................................. 3 
2.3 
Study Endpoints ................................................................................................................... 4 
 
3. SUMMARY OF STUDY PLAN  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    7 
 
4. PARTICIPANT SELECTION ............................................................................................................. 8 
4.1 
Inclusion Criteria ................................................................................................................... 8 
4.2 
Exclusion Criteria .................................................................................................................. 9 
 
5. AGENT ADMINISTRATION 
5.1 
Dose Regimen and Dose Groups ......................................................................................... 9 
5.2 
Study Agent Administration .................................................................................................. 9   
5.3 
Contraindications ............................................................................................................... 10 
5.4 
Concomitant Medications ................................................................................................... 10 
5.5 
Dose Modification ............................................................................................................... 10 
 
6. PHARMACEUTICAL INFORMATION ............................................................................................. 11 
6.1 
Metformin ........................................................................................................................... 11 
6.2 
Reported Adverse Events and Potential Risks .................................................................... 11 
6.3 
Source of Study Agent ........................................................................................................ 13 
6.4 
Agent Storage and Distribution ........................................................................................... 13 
6.5 
Registration/Randomization ................................................................................................ 13 
6.6 
Blinding and Unblinding Methods ........................................................................................ 13 
6.7 
Agent Disposal ................................................................................................................... 13 
 
7. CLINICAL EVALUATIONS AND PROCEDURES 
7.1       Schedule of Events  ............................................................................................................. 14 
7.2 
Consenting/Screening .......................................................................................................... 15 
7.3 
Evaluation During Study Intervention .................................................................................... 15 
7.4 
Evaluation at Completion of Study Intervention ..................................................................... 17 
7.5 
Post-intervention Follow-up Period ....................................................................................... 17 
 
8. SPECIMEN MANAGEMENT ........................................................................................................... 17 
8.1 
Collection and Handling Procedures ................................................................................... 17 
8.2 
Shipping Instructions .......................................................................................................... 18 
8.3 
Tissue Banking ................................................................................................................... 18 
 
9. STATISTICAL CONSIDERATIONS  ............................................................................................... 18 
9.1        Analysis Plan ...................................................................................................................... 19 
9.2        Sample Size Justification .................................................................................................... 20 
9.3        Interim Analysis .................................................................................................................. 20 
        
10.  DATA AND SAFETY MONITORING PLAN .................................................................................... 20 
10.1      Protocol Risk Level ............................................................................................................. 20 
10.2      Identification of the DSMB Obligated for Oversight Responsibilities ..................................... 20 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
iv 
 
10.3      Identification of the Entity Obligated for Obligated for Routine Monitoring Duties ................. 20 
10.4      Monitoring Progress and Data Review Process ................................................................... 20 
 
11. Description and Reporting of Adverse Events ............................................................................. 21 
11.1       Adverse Events  ................................................................................................................ 21 
11.2       Serious Adverse Events ..................................................................................................... 22 
11.3       Plan for Assuring Data Accuracy and Protocol Compliance ................................................ 23 
 
12. REGULATORY CONSIDERATIONS ............................................................................................... 23 
12.1       Regulatory Board Review .................................................................................................. 23 
12.2       Compliance with Protocol and Protocol Revisions .............................................................. 23 
12.3       Participant Informed Consent  ............................................................................................ 24 
12.4       Data Management and Safety Monitoring .......................................................................... 24 
 
13. Financing, Expenses, and/or Insurance  ...................................................................................... 24 
 
REFERENCES ...................................................................................................................................... 24 
 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
1 
 
1. 
OBJECTIVES 
 
The overall objective of this Phase II double-blind, randomized, placebo-controlled trial 
of metformin is to determine its potential effects on recognized and putative markers of breast 
cancer risk in overweight or obese premenopausal women who have metabolic syndrome. 
 
Primary objectives: 
To determine the effect of metformin intervention on breast density assessed by MRI-
acquired fat-to-water ratio (FWR-MRI). Changes in breast density will be assessed and 
compared between metformin and placebo treated groups. 
 
Secondary objectives: 
• To determine the effect of metformin intervention on metabolic disturbances and body 
weight/composition. Changes in circulating levels of insulin, IGF axis, sex steroid 
hormones, adipokines, and anthropometric measures will be assessed and compared 
between treatment groups.  
 
• To explore the application of metabolomics as a systems biology approach to assess 
the chemopreventive mechanisms of metformin. The global profiles of biochemicals 
and metabolites in nipple aspirate fluid (NAF) and plasma will be assessed through 
unbiased metabolome wide analysis to determine the metabolic changes induced by 
metformin in comparison with placebo. We will also explore whether metformin-
induced metabolic changes correlate with metformin-induced changes in markers of 
breast cancer risk or side effects.  In a cross-sectional fashion, we will explore the 
correlations between baseline metabolic features with breast density and circulating 
levels of hormones and cytokines.   
 
Exploratory objectives: 
To determine the effect of metformin intervention on tissue architecture as well as 
cellular and molecular targets in breast tissue collected in a subgroup of participants. The tissue 
level information will also allow us to conduct correlative studies with our primary endpoint and 
secondary endpoints. These analyses will provide the much needed insight on the potential 
mechanisms of metformin action at the tissue level and aid in validating FWR-MRI and nipple 
aspirate as surrogate measures for tissue changes with metformin intervention. 
 
2. 
BACKGROUND 
 
2.1 
Significance 
 
 
Obesity-associated breast cancer risk 
A recent report indicates that two-thirds of the U.S. adults are overweight or obese (1). 
High adiposity is a major risk factor for a number of chronic diseases, including type 2 diabetes, 
cardiovascular diseases, and certain types of cancer, including postmenopausal breast cancer 
(2-5). The increased postmenopausal breast cancer risk in women with high adiposity is likely to 
be attributed to multiple metabolic disturbances including altered circulating sex steroid 
hormones, hyperinsulinemic insulin resistance, altered expression and secretion of adipokines 
from adipose tissue, increased production of pro-inflammatory cytokines, and increased 
oxidative stress.  
 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
2 
 
Metformin for Reduction of Obesity-Associated Breast Cancer Risk Metformin, a 
widely used antidiabetic drug, exerts favorable effects on multiple metabolic disturbances which 
may lead to reduction of breast cancer risk in women with high adiposity.  Metformin has been 
shown to reduce circulating insulin levels (reviewed by (6)), increase insulin-like growth factor 
binding protein (IGF-BP) 1 (7, 8), decrease serum testosterone and androstenedione levels (9, 
10), and increase serum sex steroid binding globulin (9, 10) in non-diabetic women with 
polycystic ovary syndrome (POS). Reduction in serum insulin levels was also observed in non-
diabetic breast cancer patients with metformin treatment (11).  In diabetics, metformin treatment 
resulted in favorable changes in circulating levels of leptin and adiponectin (12, 13). 
Furthermore, studies have shown that metformin intervention resulted in weight reduction in 
overweight or obese patients without type 2 diabetes, although these trials were mostly small 
and of weak design and 
weight reduction was 
not observed in all 
studies (reviewed by 
(14)).  
 
In addition to the 
indirect effects, 
metformin may exert a 
direct effect in 
mammary tissue 
through the activation of 
the AMP-activated 
protein kinase (AMPK) 
signaling pathway, 
leading to an 
antiprolierative effect 
and induction of 
apoptosis (15-18). However, metformin is an organic cation at physiological pH. Its cellular 
uptake generally requires the presence of cell surface transporters. It is not known whether the 
human mammary tissue expresses the transporters for metformin to exert its direct effect.     
 
Epidemiological and Clinical Studies  
Case control and cohort studies investigating the relationship between diabetes and 
cancer found that treatment with metformin appears to substantially reduce the risk for 
development of cancer in diabetics (19, 20), including breast cancer (21-24).  Given the 
retrospective nature of these studies and the possibility that the comparison treatments (such as 
sulfonylureas or exogenous insulin) may increase risk, randomized, placebo-controlled 
intervention trials are clearly needed to assess the breast cancer preventive activity of 
metformin. It is important to note that accumulating evidence suggests that type 2 diabetes and 
obesity share biological mechanisms for their association with breast cancer (reviewed by (25)). 
Therefore, metformin would have high potential for breast cancer risk reduction in non-diabetics 
with high adiposity.  
 
Recent window-of-opportunity neoadjuvant trials reported clinical activity of metformin in 
non-diabetic women with operable invasive breast cancer after 2-4 weeks of metformin. In two 
small non-placebo controlled trials, short-term metformin intervention prior to surgery resulted in 
decreased tumor cell proliferation (26, 27). A considerably larger randomized, placebo-
controlled trial did not show an overall decrease in tumor cell proliferation after 4 weeks of 
metformin intervention (28). However, subgroup analyses showed a decrease in tumor cell 
proliferation and serum insulin levels in women with high adiposity or insulin resistance, 
 
 
Figure 1. Simplified schematic of the potential mechanisms of action of 
metformin in prevention of obesity-associated breast cancer 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
3 
 
suggesting the importance of considering the metabolic characteristics of the study population 
(28).  
   
2.2 
Study Design and Rationale  
The overall objective of the proposed study is to evaluate the potential activities of 
metformin for breast cancer risk reduction in overweight or obese premenopausal women who 
have metabolic syndrome. This study population is at increased risk for postmenopausal breast 
cancer and has a high prevalence of metabolic disturbances. In addition, clinical and animal 
studies suggest that metformin may only exert tumor suppressive effects in metabolic 
phenotypes of high adiposity and metabolic syndrome (28-30). We select to study 
premenopausal women over postmenopausal women because premenopausal women have a 
higher baseline breast density which may allow for more notable detection of reduction in breast 
density (primary study endpoint). Cuzick and colleagues showed that 4.5 years of tamoxifen 
intervention was associated with a 13% absolute reduction in breast density among women 
aged 45 years or younger, compared with only 1% reduction among women older than 55 years 
(31).      
 
The primary study aim is to determine the metformin effect on the risk features of the 
breast by assessing the modulation effect on breast density.  While the specific relationship 
between breast density and breast cancer has not been established, breast density is one of the 
strongest and most consistent risk factors for breast cancer. Studies suggest that women with 
the dense tissue in more than 60-75% of the breast are at 4-6-fold greater risk of developing 
breast cancer than those with no dense tissue (32-34). In addition, density in more than 50% of 
the breast could account for about a third of breast cancer (reviewed by (35)). The biological 
mechanism behind the association between breast density and breast cancer is not completely 
understood, but breast density may reflect the amount and proliferation of epithelial and stromal 
cells in the breast and exposure of the breast to mitogens and mutagens (reviewed by (36)). 
Importantly, breast density is modifiable by exposures that influence breast cancer risk (31, 37-
40). We hypothesize that metformin intervention would reduce breast density because 
metformin has been shown to decrease breast cell proliferation and modulate the IGF axis (7, 8, 
26, 27) and both of these have been associated with variation in breast density (41-44).  In the 
proposed project, breast density will be assessed by FWR-MRI, a novel, three-dimensional 
measure of breast density that will provide more sensitive and quantitative detection of changes 
in breast density than mammographic measure.  
 
The study will also determine whether the metformin intervention will result in favorable 
changes in metabolic disturbances and anthropometric measures in the study cohort. Favorable 
changes in these metabolic disturbances would provide clinical evidence for metformin in risk 
reduction for breast cancer and other chronic diseases.  In addition, we will explore the 
application of metabolomics as a systems biology approach to assess the chemopreventive 
mechanisms of metformin and to understand metabolic features affecting systemic and tissue 
markers of breast cancer risk.  
 
Findings from this study will have wide public health impact because of the growing 
overweight and obese populations at risk for multiple diseases. With its demonstrated effect in 
reducing the incidence of diabetes in high risk adults (45), metformin would have a high level of 
acceptance and uptake in at risk women with high adiposity if it has also been shown to exert 
favorable activities in breast cancer risk reduction. Importantly, a 10-year cost-effectiveness 
study showed that metformin is more cost-effective than life-style intervention for diabetes 
prevention (46). Considering the challenges in maintaining a healthy life style by the majority of 
general public and the pleiotropic activities of metformin for multiple metabolic disorders, 
metformin could be developed as an integrated pharmacological approach for at risk women 
with high adiposity for prevention of multiple diseases. 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
4 
 
 
2.3 
Study Endpoints 
2.3.1 Breast Density  
The primary endpoint is changes in breast density, assessed by MRI-acquired fat-to-
water ratio. Measures of mammographic breast density suffer from well recognized limitations 
that reduce precision, reproducibility, sensitivity and accuracy (47, 48).  Mammography also 
imparts ionization radiation to the breast.  Although added risk from repeated mammography is 
small for the general population (13 per 100,000), it is not insignificant (49), and may be greater 
for women at risk for breast cancer.  Drs. Stopeck and Thompson (Co-Is) have conducted a pilot 
study of 29 women to determine the 
application of FWR-MRI to 
quantitatively measure density in the 
breast without irradiating the breast or 
use of contrast agents. The study 
team has optimized data acquisition 
and image feature extraction (< 5 
min/scan) and demonstrated high 
reproducibility (r2=0.997) of FWR-MRI 
applied to images of the breast. Figure 
2 shows example images and FWR-
MRI histograms in relation to their 
corresponding BIRADS categories. 
Importantly, the study team has 
selected the fraction of voxels with 
more water than fat content (Fra50) as 
the primary measure of breast density derived from FWR-MRI which includes the area of the 
histogram with < 50% fat. The log(Fra50) measure of breast density produces results that are 
highly correlated with visualized % density as seen on standard mammography (Spearman rho 
= 0.946, p < 0.0001, Figure 3). The log(Fra50) is easily derived from FWR-MRI imaging, 
correlates strongly with mammography density and provides an optimized dynamic range for 
measuring small changes in density. FWR-MRI for breast density assessment has been 
implemented at UACC in two NCI-funded ongoing trials led by the Co-Is. 
  
Another major strength of FWR-MRI over 
mammography lies in the number of non-
compressed images/segments that can be taken 
and used in the analysis, yielding a three 
dimensional image of the breast. This is 
especially relevant in our proposed cohort in 
accurate assessment of breast density because 
a greater compressed breast thickness is 
expected in overweight and obese women than 
normal-weight women. FWR-MRI also allows 
dense areas to be located within the breast 
rather than seeing a single compressed 
measurement and can be re-assessed using 
shorter intervals at no risk or harm to the women 
on study.    
 
2.3.2 Metabolic Disturbances and Anthropometric Measures 
The study will determine the effect of metformin intervention on metabolic disturbances 
(including measures of circulating levels of insulin, sex steroid hormones, insulin-like growth 
factor axis, and adipokines) and anthropometric measures.   
 
Figure 3. Mammographic density vs. FWR-
MRI defined by log(Fra50) 
log (FWR Fr50) 
-5
-4
-3
-2
-1
0
Left Breast Density (%)
0
20
40
60
80
100
 
Figure 2. Example images and FWR histograms 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
5 
 
 
Insulin. Insulin exerts a mitogenic effect on both normal and neoplastic breast epithelial 
cells.  Hyperinsulinemia and insulin resistance are hypothesized mechanisms underlying the link 
between obesity and breast cancer risk and prognosis  (50).  One mechanism by which high 
levels of insulin might promote breast cancer is by causing a reduction in sex hormone binding 
globulin production by the liver (51, 52) with a consequent elevation in bioavailable estradiol and 
stimulation of tumor cell proliferation.  Insulin can also induce aromatase activity (53), thus 
producing a further increase in estrogen biosynthesis.  A positive correlation between fasting 
serum insulin levels and breast cancer risk was observed in several studies (54-56).  Metformin 
has been shown to reduce circulating insulin levels in women with polycystic ovary syndrome 
(reviewed by (6)) and in non-diabetic breast cancer patients (11).   
 
Sex Steroid Hormones.  Breast cancer risk is also partially determined by several 
hormone-related factors. A large case-control study nested within the European Prospective 
Investigation into Cancer and Nutrition (EPIC) showed that premenopausal women with 
elevated serum levels of testosterone or androstenedione had an increased risk of breast 
cancer (57). The finding is consistent with observations from two other smaller prospective 
studies (58, 59). Results on the relationship between breast cancer risk and pre-menopausal 
blood levels of estradiol are less consistent (57, 59-61). Metformin has been shown to decrease 
serum testosterone and androstenedione levels (9, 10) and increase serum sex steroid binding 
globulin (9, 10) in women with polycystic ovary syndrome.  
 
Insulin-like Growth Factor Axis. Insulin-like growth factors 1 and 2 are among the 
most potent stimulators of cell proliferation and differentiation in humans.  Their bioavailability is 
regulated by a family of IGF binding proteins (IGF-BP), which can bind and inactivate IGFs but 
also increase their activity under specific conditions. IGF-BP3 binds approximately 75-90% of 
circulating IGF-1 and IGF-2 and may be the most important determinant of IGF bioavailability 
(62).  These systemic hormones are expressed in most tissues including the breast and are 
locally acting growth factors with paracrine and autocrine functions. Epidemiological evidence 
suggests that elevated levels of serum IGF-1 or relative ratios of IGF-1 to IGF-BP3 may be 
associated with an increased risk of breast cancer in premenopausal women (63-65).  
Metformin has been shown to increase IGF-BP1 but have no effect on IGF-1 in women with 
polycystic ovary syndrome (7, 8).   
 
Adipokines. Leptin and adiponectin are adipokines produced predominantly or 
exclusively by adipocytes of white adipose tissue.  A number of studies have shown that low 
serum adiponectin levels and high serum leptin levels are associated with an increased risk for 
breast cancer (66-70), although some studies found no association between circulating leptin 
level and breast cancer risk (71-73).  Nevertheless, studies have shown that leptin 
measurement is more sensitive to a number of variables related to specimen collection (74, 75). 
The circulating leptin concentration is directly proportional to the degree of adiposity (76).  In 
addition, serum leptin levels are 2-3 times higher in women than in men after adjusted for age 
and BMI (77).  Leptin is a mitogen for various cell types including normal and transformed 
breast epithelial cells (78, 79).  Leptin has been shown to induce proliferation (80-82), increase 
the expression of proteolytic enzymes that are essential in metastatic process (83), and 
stimulate angiogenesis (84, 85).  In addition, leptin interferes with insulin signaling, and insulin 
resistance syndrome is accompanied by hyperleptinaemia as well as hyperinsulinaemia, which 
allows for excessive endocrine activity of these proteins at target sites (86-88).  In contrast to 
leptin, there is an inverse relationship between the plasma adiponectin concentration and body 
fat mass (89, 90).  Its production in adipose tissue is suppressed in the insulin resistance 
syndrome and obesity with consequent hypoadiponectinaemia (91).  Adiponectin has been 
shown to suppress proliferation of human breast cancer cells (82, 92, 93).  It was also reported 
to suppress angiogenesis by a process which involves activation of members of the caspase 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
6 
 
group of apoptotic factors (94).  In diabetics, metformin treatment resulted in favorable changes 
in circulating levels of leptin and adiponectin (12, 13).  
 
Anthropometric Measures. Studies suggested that weight reduction reduces risk of 
postmenopausal breast cancer.  For example, in the Iowa Women’s Health Study, women who 
lost >5% of their body weight before menopause had 40% fewer breast cancers in the 
postmenopausal period compared with women who continued to gain weight (95). In addition to 
weight gain, body fat distribution has also been suggested to play a role in the risk of breast 
cancer. Positive association between central adiposity and breast cancer risk was observed in 
some studies (96-99). Studies have shown that metformin intervention resulted in weight 
reduction and decreased waist circumference in overweight or obese individuals without type 2 
diabetes, although these trials were small and of weak design (reviewed by (14)).   
 
2.3.3 Metabolomics in NAF and plasma  
The study will explore the application of metabolomics as a systems biology approach to 
assess the chemopreventive mechanisms of metformin. The global profiles of biochemicals and 
metabolites in nipple aspirate fluid and plasma will be assessed through unbiased metabolome 
wide analysis to determine the metabolic changes induced by metformin in comparison with 
placebo. We will also explore whether metformin-induced metabolic changes correlate with 
metformin-induced changes in markers of breast cancer risk or side effects.  In a cross-sectional 
fashion, we will explore the correlations between baseline metabolic features with breast density 
and circulating levels of hormones and cytokines.  
  
Metabolomics is a comprehensive analysis of metabolite levels in whole organisms and 
the investigation of how stimuli such as diet, lifestyle, environment, genetic effects, and 
pharmaceutical interventions influence the metabolite levels (100). Metformin has demonstrated 
diverse biological activities in different cells/tissues. Application of metabolomics to this project 
would represent a systems biology approach to understand the mechanisms for metformin-
associated changes in markers of breast cancer risk or adverse effects in healthy 
overweight/obese women. A recent pilot metabolomics study in 15 type 2 diabetic patients 
showed that treatment with metformin for 3 months resulted in changes in a number of 
endogenous metabolites (101). In addition to its effects on glucose and lipoprotein metabolism 
pathways, metformin also modulated bacteria and nutrition metabolism (101).  
 
For the proposed project, we also plan to explore the metabolomic profiles in NAF. NAF 
contain breast epithelial cells as well as proteins and other cellular metabolites secreted from 
the ductal epithelium. It can be collected noninvasively, inexpensively, and repeatedly with 
minimal or no discomfort. We have had extensive experience in NAF collection and 
determination of biomarkers in NAF in early phase clinical trials. We have shown a reduction in 
prostaglandin E2 levels in NAF 
following a 6-week intervention of 
sulindac in women at increased breast 
cancer risk (102). In our recently 
completed study, we found that 
menopausal status significantly 
affected expression of certain proteins 
in NAF but the effect is less notable in 
plasma (see Table 1), suggesting that 
NAF biomarkers may provide 
information about the breast 
microenvironment that might not be 
reflected in plasma.     
 
Table 1. NAF and plasma biomarker expression differs 
by menopausal status.  
NAF 
EGF 
(ng/g PT) 
TGF-β1 
(ng/g PT) 
Adiponectin 
(µg/g PT) 
Pre-menopausal 
7,759±2,854 
2,079±3,027 
11.6±9.1 
Post-menopausal 
2,532±4,354 
361±357 
26.3±28.5 
P-value 
0.0022 
<0.0001 
0.0880 
Plasma 
EGF 
(pg/ml) 
TGF-β1 
(ng/ml) 
Adiponectin 
(µg/ml) 
Pre-menopausal 
34.1±29.0 
9.92±3.77 
9.67±4.19 
Post-menopausal 
21.6±13.5 
10.47±3.13 
13.37±6.14 
P-value 
0.2891 
0.5097 
0.0607 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
7 
 
2.3.4 Tissue Biomarkers 
The study will also explore the effect of metformin intervention on tissue biomarkers in 
breast tissue collected in a subgroup of participants. The collection of pre- and post-treatment 
tissue biopsy in a subset of subjects will allow us to assess changes in tissue architecture as 
well as to measure change in metformin molecular and metabolic targets in normal breast 
tissue. In addition, tissue level information will allow us to conduct correlative studies with our 
primary endpoint (change in breast density) and secondary endpoints (change in metabolites in 
NAF). These analyses will provide much needed insight on the potential mechanisms of 
metformin action at the tissue level and aid in validating FWR-MRI and NAF as surrogate 
measures for tissue changes with metformin intervention.  
 
The ongoing sulindac/AI trial (IRB#12-0080-04) led by Drs. Stopeck and Thompson has 
established the infrastructure for performing ultrasound-guided core needle biopsy for clinical 
research.  Currently, 100% of enrolled participants have consented to undergo the optional core 
needle biopsy procedures and have found the procedure acceptable and relatively pain-free.  All 
have tentatively agreed to undergo a second procedure for breast tissue procurement as well. 
We plan to adapt the experience gained from the sulindac/AI trial to facilitate the collection of 
breast tissue in the metformin study. We conservatively estimate that 50% of women will 
consent to provide core biopsy specimens.    
 
3. 
SUMMARY OF STUDY PLAN 
 
 
This is a Phase II double-blind, randomized, placebo-controlled trial of metformin to 
determine its potential effects on recognized and putative markers of breast cancer risk in 
overweight or obese premenopausal women who have metabolic syndrome.  The study 
endpoints are modulation of breast density and metabolic disturbances, risk factors associated 
with breast cancer.  In addition, the study will explore the application of metabolomics as a 
systems biology approach to assess the chemopreventive mechanisms of metformin and to 
understand factors affecting markers of breast cancer risk. The study will also explore the effect 
of metformin intervention on tissue architecture as well as cellular and molecular targets in 
breast tissue collected in a subgroup of participants. 
 
At the consenting/screening visit, participants will sign informed consent and undergo 
the following procedures for screening: collection of medical history and medication usage 
history, demographic information (age, race/ethnicity), anthropometric measurements (weight 
(wt), height, waist circumference, waist-hip ratio), breast cancer risk information (family and 
personal history of breast cancer, age at menarche, parity, and prior breast biopsy), information 
on menstrual patterns/cycles, and a fasting blood sample for complete blood count with 
differential (CBC/w diff) and comprehensive metabolic panel (CMP).  
 
Participants who meet all selection criteria will return in the midluteal phase of the 
menstrual cycle, when feasible, to undergo baseline evaluation including collection of a fasting 
blood for research biomarkers, collection of NAF for metabolomic analysis, MRI assessment of 
breast density, collection of wt, waist circumference, and waist-hip ratio measurements, and the 
optional core needle biopsy for breast tissue collection. Women who cannot fit into the MRI 
scanner due to the large body size will continue the study and undergo all other study 
procedures. Participants will also complete the Arizona Food Frequency Questionnaire (AFFQ) 
to measure usual dietary intake and the Arizona Activity Frequency Questionnaire (AAFQ) to 
assess usual physical activity.    
 
Following completion of baseline evaluation, participants will be randomized to receive 
metformin or placebo for 12 months. We plan to randomize 150 eligible participants (75 per 
arm).  With an anticipated attrition rate of 20% or less, we expect to have at least 60 women per 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
8 
 
arm completing the intervention.  Participants will be asked to take one 850 mg metformin or 
one placebo tablet daily with a meal for the first four weeks, then two 850 mg metformin or two 
placebo tablets daily with meals for the remainder of the study. The same starting dose and 
gradual dose escalation up to 2,000 mg per day is used to minimize gastrointestinal symptoms 
for glycemic control in diabetics (GLUCOPHAGE prescribing information).  
 
Participants will be asked to keep an adverse event diary and menstrual calendar 
throughout the study.  In addition, participants will be provided with an intake calendar for 
recording medication usage. Study personnel will contact study participants within a week after 
study agent has been initiated and within a week following scheduled dose increase to assess 
compliance and any potential problems.  Participants will return to the clinic at months 3, 6, and 
9 after initiation of agent intervention to undergo safety and compliance evaluation.  For the 
month 6 visit, participants will be scheduled to return to the clinic in the midluteal phase of the 
menstrual cycle, when feasible. In addition to undergoing study procedures described above, 
participants will undergo wt, waist circumference, and waist-hip ratio measurements, have a 
fasting blood and NAF collected for research biomarkers, undergo MRI assessment of the 
breast if MRI was performed at the baseline visit, return unused pills and receive a new supply 
of study medication, and undergo the optional core needle biopsy.   Study personnel will contact 
study participants at least once and as needed between clinic visits to assess compliance and 
any potential problems.    
 
At the end of the 12-month agent intervention, participants will return to the clinic in the 
midluteal phase of the menstrual cycle, when feasible, to collect wt, waist circumference, and 
waist-hip ratio measurements, return unused drugs, review side effects, and have a fasting 
blood sample collected for safety labs and research biomarkers. Participant will also undergo 
NAF collection for metabolomics, and MRI assessment of the breast if MRI was performed at 
the baseline visit. Participants will also complete the AFFQ and AAFQ to assess any changes in 
dietary intake and physical activity during the intervention.  Following the study intervention, 
participants will be followed for 2 weeks for any adverse reactions.     
 
     
4. 
PARTICIPANT SELECTION 
 
4.1 
Inclusion Criteria 
• 
Premenopausal women  
• 
21-54 years of age 
• 
No change in menstrual patterns for the past 6 months preceding the time of 
registration 
• 
Have a BMI of 25 kg/m2 or greater 
• 
Large waist circumference  
o ≥ 88 cm (≥35 inches) or  
o ≥ 80 cm (≥31 inches) for Asian Americans, individuals with polycystic 
ovary syndrome, or individuals with non-alcoholic fatty liver disease 
• 
Have at least one other component of metabolic syndrome (103) reported below: 
o Elevated triglycerides (≥ 150 mg/dL (1.7 mmol/L)) or on drug treatment for 
elevated triglycerides  
o Reduced HDL-C (< 50 mg/dL (1.3 mmol/L)) or on drug treatment for 
reduced HDL-C 
o Elevated blood pressure (≥ 130 mm Hg systolic blood pressure or ≥85 
mm Hg diastolic blood pressure) or on antihypertensive drug treatment in 
a patient with a history of hypertension 
o Elevated fasting glucose (≥100 mg/dL)  

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
9 
 
• 
Mammogram negative for breast cancer within the 12 months preceding the time 
of registration for women ≥ 50 years of age 
• 
Ability to understand and the willingness to sign a written informed consent 
document 
 
4.2 Exclusion Criteria 
 
• 
Postmenopausal women 
o Amenorrhea for at least 12 months (preceding the time of 
registration), or 
o History of hysterectomy and bilateral salpingo-oophorectomy, or 
o At least 55 years of age with prior hysterectomy with or without 
oophorectomy, or  
o Age 35 to 54 with a prior hysterectomy without oophorectomy OR with 
a status of ovaries unknown with documented follicle-stimulating 
hormone level demonstrating elevation in postmenopausal range 
• 
Women who are pregnant, planning pregnancy within the next year, or 
lactating/breastfeeding 
• 
On treatment with any drug for diabetes 
• 
Have uncontrolled intercurrent illness including, but not limited to, ongoing or 
active infection, symptomatic congestive heart failure, unstable angina pectoris, 
cardiac arrhythmia, or any illness that would limit compliance with study 
requirements 
• 
Have received chemotherapy and/or radiation for any malignancy (excluding 
non-melanoma skin cancer and cancers confined to organs with removal as only 
treatment) in the past 5 years (preceding the time of registration) 
• 
Have received other investigational agents within the past 3 months (preceding 
the time of registration)   
• 
Have a history of lactic acidosis or risk factors for lactic acidosis 
• 
Have renal disease or dysfunction (creatinine ≥ 1.4 mg/dL)  
• 
Have hepatic dysfunction (bilirubin > 1.5 x ULN unless with Gilberts syndrome or 
AST/ALT > 3 x ULN) 
• 
Have a history of alcoholism or high alcohol consumption (average of > 3 
standard drinks/day) 
• 
Have a history of allergic reactions to metformin or similar drugs  
• 
Have a history of severe claustrophobia 
• 
Have electrically, magnetically, or mechanically activated implants including 
cardiac pacemaker, cochlear implants, magnetic surgical clips or prostheses 
• 
Have breast implants 
  
 
 
5. 
AGENT ADMINISTRATION 
 
5.1  
Dose Regimen and Dose Groups 
• 
Subjects will be randomly assigned to the following treatment groups: 
• 
Metformin, 850 mg tablets 
• 
Placebo tablets 
• 
Duration of treatment is 12 months (52 ± 4 wks).  
 
5.2 
Study Agent Administration 
• 
For the first four weeks, 1 metformin or placebo tablet will be taken daily. 
• 
For the remaining treatment period, 2 metformin or placebo tablets will be taken 
daily. Depending on the tolerability, 2 tablets may be taken together with a meal 
or taken separately (i.e., one tablet twice a day).   

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
10 
 
• 
Tablets should be taken with food, preferably with the evening meal. 
• 
Tablets should be swallowed with a full 8 oz glass of water. 
 
 
5.3. 
Contraindications 
Metformin is contraindicated in patients with 
• 
Renal disease or renal dysfunction 
• 
Known hypersensitivity to metformin hydrochloride 
• 
Acute or chronic metabolic acidosis 
• 
Hepatic impairment, as defined in the exclusion criteria 
 
Because use of iodinated contrast materials may result in acute alteration of renal 
function and have been associated with lactic acidosis in patients receiving metformin, patients 
who plan to undergo radiologic studies involving intravascular administration of iodinated 
contrast materials will not be permitted to begin study medication until at least 48 hours 
following the procedure and only after renal function has been re-evaluated and found to be 
normal (serum creatinine < 1.4 mg/dL).  
 
5.4 
Concomitant Medications 
Participants may not use non-study metformin or other biguanides while on study.  
 
Cationic drugs (e.g., amiloride, digoxin, morphine, procainamide, quinidine, quinine, 
cimetidine, ranitidine, triamterene, trimethoprim, or vancomycin) have the potential for 
interaction with metformin by competing for common renal tubular transport systems which may 
interfere with the disposition of metformin. Although such interactions remain theoretical (except 
for cimetidine), careful patient monitoring is recommended in patients who are taking cationic 
medications that are excreted via the proximal renal tubular secretory system.   
 
All medications (prescription and over-the-counter), vitamin and mineral supplements, 
and/or herbs taken by the participant will be documented on the concomitant medication CRF 
and will include: 1) start and stop date, dose and route of administration, and indication. 
Medications taken for a procedure (e.g., biopsy) should also be included. 
 
If a subject requires a radiologic exam involving intravascular administration of iodinated 
contrast materials while participating in the study, she must discontinue study agent for at least 
48 hours prior to having the exam and will not be permitted to restart study medication until at 
least 48 hours following the procedure and only after renal function has been re-evaluated and 
found to be normal (serum creatinine < 1.4 mg/dL). 
 
5.5 
Dose Modification  
The NCI Common Terminology Criteria for Adverse Events (CTCAE) Version 4 will be 
used for toxicity reporting. For grade 1 adverse events or less, no dose modification will be 
made.   
 
For grade 2 adverse events probably or possibly related to study agent persisting for 
more than three days during the first 4 weeks of dosing with 1 tablet of 850 mg metformin or 
placebo daily, study drug will be held.  Study drug will be reintroduced at the same dose when 
the adverse event resolves to Grade 1 or below within 2 weeks.  If the Grade 2 event does not 
resolve to Grade 1 or below within 2 weeks, participants will be removed from the study and 
followed for resolution of the adverse event.  
 
For grade 2 adverse events probably or possibly related to study agent persisting for 
more than three days after taking 2 tablets of 850 mg metformin or placebo daily, study drug will 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
11 
 
be held.  Study drug will be reintroduced at 50% dose (1 tablet of 850 mg metformin or placebo 
daily) when the adverse event resolves to Grade 1 or below within 2 weeks.  If the Grade 2 
event does not resolve to Grade 1 or below within 2 weeks, participants will be removed from 
the study and followed for resolution of the adverse event. After reinstitution of 50% dose (1 
tablet of 850 mg metformin or placebo daily) for a minimum of 2 weeks, the full dose (2 tablets 
of 850 mg metformin or placebo daily) may be reintroduced at the discretion of the study 
physician. If the Grade 2 adverse event recurs and persists for more than three days following 
reinstitution of the full dose and is considered definitely, probably or possibly related to study 
agent, the study agent will be held and reintroduced at 50% dose (1 tablet of 850 mg metformin 
or placebo daily) if the adverse event resolves to Grade 1 or below within 2 weeks. The dose 
will then be kept at the reduced dose for the duration of the study. If the Grade 2 event does not 
resolve to Grade 1 or below within 2 weeks, participants will be removed from the study and 
followed for resolution of the adverse event.  If participants do not wish to be re-challenged with 
the full dose, they may remain on study at 50% dose. 
 
For Grade 2 or Grade 3 adverse events not considered related to study agent, the study 
agent may be stopped and resumed at the discretion of study physician.  
 
Grade 3 events possibly, probably, and definitely related to study agent, and Grade 4 
events regardless of relationship to study agent, will result in permanent withdrawal of study 
agent.  Subjects will be followed for resolution of adverse events.  The Principal Investigator and 
Medical Director will be notified immediately of any grade 3 or 4 adverse events.  The study 
investigators will decide if the adverse event is related to the agent.  
 
All AEs, including lab abnormalities will be followed for 2 weeks or longer for resolution 
according to good medical practices and documented as such. 
 
 
6. 
PHARMACEUTICAL INFORMATION 
 
6.1 
Metformin  
 
Metformin is a biguanide indicated as an adjunct to diet and exercise to improve 
glycemic control in adults and children with type 2 diabetes mellitus. Metformin is one of the 
most widely used oral antihyperglycemic drugs in the management of type 2 diabetes. It has 
been used worldwide for over 40 years to treat type 2 diabetes, and was approved in the United 
States (US) by the Food and Drug Administration (FDA) as an antidiabetic in 1995 (104). It is 
also used off-label for polycystic ovary syndrome and metabolic syndrome. The major 
mechanism of metformin action in vivo involves suppression of hepatic gluconeogenesis and 
glucose output, which is associated with a decline in circulating glucose concentration and a 
secondary decline in insulin levels (105).  
 
Beneficial effects have also been observed in non-diabetics, including treatment of 
weight gain induced by antipsychotic medications (106), polycystic ovary syndrome (6), 
nonalcoholic fatty liver (107) and diabetes prevention in high-risk subjects (108). It has a 
demonstrated safety profile and good tolerability in both diabetics and non-diabetics. 
 
6.2 
 Reported Adverse Events and Potential Risks 
 
 
Metformin is considered to have a favorable safety profile in diabetes patients (109). In a 
US double-blind clinical trial for patients with type 2 diabetes (metformin n=141; placebo n=145), 
gastrointestinal symptoms such as diarrhea (53.2% vs. 11.7% placebo), nausea and vomiting 
(25.5% vs. 8.3% placebo), abdominal discomfort (6.4% vs. 4.8% placebo), flatulence (12.1% vs. 
5.5% placebo), indigestion (7.1% vs. 4.1% placebo), and asthenia (9.2% vs. 5.5% placebo) 
were the most common reactions to the drug. These symptoms were dose-dependent, 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
12 
 
transient, and resolved spontaneously with continued use (Glucophage (metformin 
hydrochloride tablets) label information). Diarrhea led to discontinuation of medication in 6% of 
subjects treated with metformin hydrochloride. Additional adverse reactions were reported in 1% 
to 5% of subjects receiving active drug; those more commonly reported than in the placebo 
group include abnormal stools, hypoglycemia, myalgia, lightheaded, dyspnea, nail disorder, 
rash, increased sweating, taste disorder, chest discomfort, chills, flu syndrome, flushing and 
palpitation (Glucophage (metformin hydrochloride tablets) label information). 
 
A recently published multicenter, randomized, placebo-controlled trial in patients with 
type 2 diabetes reported on vitamin B12 deficiency with long-term metformin treatment. 
Compared with placebo, metformin treatment was associated with a mean decrease in vitamin 
B12 concentration of ~19% (95% confidence interval (CI) –24% to –14%; p<0.001). The absolute 
risk of vitamin B12 deficiency (<150 pM) at study end was 7.2 percentage points higher in the 
metformin group than in the placebo group (95% CI 2.3 to 12.1; p=0.004) (110).  
 
According to the package insert, lactic acidosis is a rare, but serious, metabolic 
complication that can occur due to metformin accumulation during treatment with metformin 
hydrochloride. When it occurs, it is fatal in approximately 50% of the cases. Lactic acidosis may 
also occur in association with a number of pathophysiologic conditions, including diabetes 
mellitus and whenever there is significant tissue hypoperfusion and hypoxemia. Lactic acidosis 
is characterized by elevated blood lactate levels (>5 mmol/L), decreased blood pH, electrolyte 
disturbances with an increased anion gap, and an increased lactate/pyruvate ratio. Metformin 
plasma levels >5 μg/mL are generally found when metformin is implicated as the cause of lactic 
acidosis.  
 
Reported incidence of lactic acidosis in patients receiving metformin hydrochloride is 
very low (approximately 0.03 cases/1000 patient-years, with approximately 0.015 fatal 
cases/1000 patient-years). In more than 20,000 patient-years of exposure to metformin in 
clinical trials, there were no reports of lactic acidosis. Reported cases have occurred primarily in 
diabetic patients with significant renal insufficiency, including both intrinsic renal disease and 
renal hypoperfusion, and in those with multiple concomitant medical/surgical problems and who 
take multiple concomitant medications. Patients with congestive heart failure require 
pharmacologic management, in particular those with unstable or acute congestive heart failure 
who are at risk of hypoperfusion and hypoxemia and increased risk of lactic acidosis 
(Glucophage (metformin hydrochloride tablets) label information. 
 
The risk of lactic acidosis increases with the degree of renal dysfunction and patient age. 
Drug should be withheld in the presence of any condition associated with hypoxemia, 
dehydration, or sepsis. Because impaired hepatic function can significantly impair the ability to 
clear lactate, metformin should generally be avoided in patients with clinical or laboratory 
evidence of hepatic disease. Alcohol can potentiate the effects of metformin hydrochloride on 
lactate metabolism. Drug treatment should be temporarily discontinued prior to any intravascular 
radiocontrast study and for any surgical procedure (111). The onset of lactic acidosis is often 
subtle, and accompanied by nonspecific symptoms such as malaise, myalgia, respiratory 
distress, increasing somnolence, and nonspecific abdominal distress. There may be associated 
hypothermia, hypotension, and resistant bradyarrhythmias with more marked acidosis 
(Glucophage (metformin hydrochloride tablets) label information). 
 
In support of the previously reported low risk of lactic acidosis, a recently published 
systematic review assessed the risk with metformin use in type 2 diabetes mellitus. Pooled data 
from 347 comparative trials and cohort studies revealed no cases of lactic acidosis in 70,490 
patient-years of metformin use. The authors concluded that there was no evidence from 
prospective comparative trials or from observational cohort studies that metformin is associated 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
13 
 
with an increased risk of lactic acidosis compared to other antihyperglycemic treatments (112, 
113). 
 
Unlike sulfonylureas, metformin does not produce hypoglycemia in either type 2 diabetes 
patients or normal subjects and does not cause hyperinsulinemia (109). 
 
Carcinogenicity studies have been performed in rats (dosing duration of 104 weeks) and 
mice (dosing duration of 91 weeks) at doses up to and including 900 mg/kg/day and 
1500 mg/kg/day, respectively. Both doses are approximately four times the maximum 
recommended human daily dose of 2000 mg based on body surface area. No evidence of 
carcinogenicity was found in either male or female mice or in male rats. There was, however, an 
increased incidence of benign stromal uterine polyps in female rats at 900 mg/kg/day (109). 
Metformin was not mutagenic in the Ames, mouse lymphoma, human lymphocyte chromosome 
aberration, or mouse micronucleus tests (109).  
 
The fertility of male and female rats was unaffected by metformin when administered at 
doses as high as 600 mg/kg/day, which is approximately three times the recommended human 
daily dose based on body surface area (109). 
 
6.3  
 Source of Study Agent 
Metformin tablets, 850 mg will be purchased from a commercial source through the 
University of Arizona Cancer Center (UACC) Research Pharmacy. We will contract with Pharm 
Ops, Inc (Phillipsburg, NJ) to manufacture a clinical supply of the placebo tablets using inert 
excipients. Pharm Ops, Inc. has manufactured placebo products for a number of NCI-sponsored 
chemoprevention trials.  
 
6.4 
Agent Storage and Distribution 
Metformin and placebo tablets will be stored in the UACC Research Pharmacy at room 
temperature [20-25°C] and protected from environmental extreme. It will be dispensed to the 
study staff in light-resistant containers for distribution to the study participants.  
 
6.5 
Registration/Randomization 
Subjects will be considered registered on the date they sign the approved informed 
consent document with a member of the study staff.  Randomization will be performed using 
computer-generated random permuted blocks.   
 
6.6  
Blinding and Unblinding Methods 
To retain the blind, metformin and placebo tablets will not be identified by product names 
but by a unique randomization number.  The randomization number is assigned to the subject 
upon completion of eligibility evaluation. 
 
A list of randomization numbers linked to active or placebo agent will be generated by 
the study statistician or the designated data manager and forwarded to the UACC Research 
Pharmacy. The UACC Research Pharmacy will dispense the study agent to the study staff by 
randomization number.  The study agent bottles will be identified with the subject randomization 
number but with no product information on the label.  The study staff will dispense the product to 
subjects based on the assigned randomization number.  None of the staff interacting with 
subjects will know the link between randomization number and actual product.  The code that 
identifies the product will be kept by the study statistician or the designated data manager.    
 
Unblinding is not expected to occur until all subjects complete the intervention and data 
entry is complete.  If deemed medically necessary, study agents may be unblinded by the 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
14 
 
Principle Investigator in consultation with the Medical Director in the event of a serious adverse 
event. 
 
6.8 
Agent Disposal 
Unused agents will be returned to the clinic for compliance check and then be disposed 
according to the UA waste disposal guidelines.   

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
15 
 
  
7.      CLINICAL EVALUATIONS AND PROCEDURES 
 
7.1  
Schedule of Events 
Study Events 
Consenting/ 
Screening 
Baseline/ 
Randomization 
Intervention (12 month (52 ± 4 wks)) 
Months 1 - 3 
Month 3 Visit 
(13 ± 2 wks) 
Months 4 - 6 
Month 6 Visit 
(26 ± 4 wks) 
Months 7 - 9 
Month 9 Visit 
(39 ± 2 wks) 
Months 10 - 12 
Month 12 Visit 
(52 ± 4 wks) 
Follow up 
 
Consent, med records release 
form 
x 
 
 
 
 
 
 
 
 
 
 
Medical history, performance 
status 
x 
 
 
 
 
 
 
 
 
 
 
anthropometric measurements  
x 
x 
 
 
 
x 
 
 
 
x 
 
Vital signs (Temp, BP, Pulse) 
x 
x 
 
x 
 
x 
 
x 
 
x 
 
Concomitant meds 
x 
x 
 
x 
 
x 
 
x 
 
x 
 
Breast cancer risk assessment 
x 
 
 
 
 
 
 
 
 
 
 
Menstrual pattern/cycle review   
x 
x 
 
x 
 
x 
 
x 
 
x 
 
Menstrual cycle diary 
x 
x 
x 
x 
x 
x 
x 
x 
x 
x 
 
Fasting blood (CBC/Diff, CMP, 
lipids, FSH2,estradiol2)    
x 
 
 
 
 
 
 
 
 
x 
 
Fasting blood for research 
endpoints      
 
x 
 
 
 
x 
 
 
 
x 
 
Urine pregnancy test 
x 
x 
 
x 
 
x 
 
x 
 
x 
 
Urine for research endpoints 
 
x 
 
 
 
x 
 
 
 
x 
 
AFFQ, AAFQ 
 
x 
 
 
 
 
 
 
 
x 
 
NAF collection 
 
x 
 
 
 
x 
 
 
 
x 
 
Breast MRI3  
 
x 
 
 
 
x 
 
 
 
x 
 
Core biopsy, if consented 
 
x 
 
 
 
x 
 
 
 
 
 
Final eligibility assessment 
 
x 
 
 
 
 
 
 
 
 
 
Randomization 
 
x 
 
 
 
 
 
 
 
 
 
Dispense study agent 
 
x 
 
 
 
x 
 
 
 
 
 
Intake calendar 
 
 
x 
x 
x 
x 
x 
x 
x 
x 
 
Adverse events diary 
 
x 
x 
x 
x 
x 
x 
x 
x 
x 
x 
Adverse events review 
 
x 
 
x 
 
x 
 
x 
 
x 
x 
Return study agent 
 
 
 
 
 
x 
 
 
 
x 
 
Compliance assessment 
 
 
 
x 
 
x 
 
x 
 
x 
 
Case report form completion 
x 
x 
 
x 
 
x 
 
x 
 
x 
x 
Telephone/email contact1 
 
 
x 
 
x 
 
x 
 
x 
 
 
1 Study personnel will contact subjects within a week after study agent has been initiated and within a week following 
scheduled dose increase to assess compliance and any potential problems. Additional periodic telephone or email contact will 
occur between study visits and as needed to review study procedures, adverse events, concomitant medications, and to 
address any subject concerns.  
2 FSH (follicle-stimulating hormone) and/or estradiol at screening for women with uncertain menopausal status.  
3 Women who cannot fit into the MRI scanner due to the large body size will continue the study and undergo all other study 
procedures. 
 
 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
16 
 
 
7.2  
Consenting/Screening  
Potential subjects will present to clinic for a detailed discussion of the protocol with the 
study coordinator.  Signed informed consent will be obtained prior to any study-related activities 
or procedures being conducted.  Subjects are registered onto the protocol on the day of 
consent.  Participants will then undergo the following procedures for screening. 
• 
Review of medical history and medication usage history  
• 
Collection of demographic information (age, race/ethnicity).  
• 
Collection of anthropometric measurements (weight (wt), height, waist 
circumference, waist-hip ratio). Body weight will be measured with participants 
standing on a calibrated scale with minimal movement with hands by their side and 
shoes and excess clothing removed.  Waist and hip circumference will be measured 
in a standing position with a flexible tape. Waist circumference will be measured at 
the midpoint between the lowest rib and the top of the iliac crest on the bare 
abdomen. Participants will be asked to relax and exhale for the measurement. Hip 
circumference will be measured at the level of the greatest protrusion of the gluteal 
muscles, with minimal clothing. Participants will be asked to stand with their weight 
evenly distributed on both feet and legs slightly parted, making sure not tense the 
gluteal muscles.  When recording the measurement, the study personnel will ensure 
that the tape is not too tight or too loose, is lying flat on the skin, and is horizontal. 
• 
Collection of breast cancer risk information (family and personal history of breast 
cancer, age at menarche, parity, and prior breast biopsy).  
• 
Collection of information on menstrual patterns/cycles.  
• 
Measures of vital signs (temperature, blood pressure and pulse). 
• 
A fasting blood sample for complete blood count with differential (CBC/w diff), 
comprehensive metabolic panel (CMP), lipids, and follicle-stimulating hormone (FSH) 
and/or estradiol for women with uncertain menopausal status. The screening blood 
work may be repeated, if clinically indicated. 
• 
Urine pregnancy test.  
 
7.3 
Evaluations During Study Intervention 
Participants who meet all selection criteria will undergo the following baseline 
procedures. When feasible, these procedures will be scheduled in the midluteal phase of the 
menstrual cycle.  
 
• 
Anthropometric measurements including wt, waist circumference, waist-hip ratio. 
• 
A fasting blood for research biomarkers.   
• 
Collection of urine for urine pregnancy test and research tests.  
• 
Vital signs. 
• 
Update information on menstrual patterns/cycles.  
• 
Update medication usage. 
• 
Completion of the Arizona Food Frequency Questionnaire (AFFQ) to measure usual 
dietary intake and the Arizona Activity Frequency Questionnaire (AAFQ) to assess 
usual physical activity. 
• 
Nipple aspirate fluid, for those who are able to produce NAF, for metabolomic 
analysis. Breasts will be warmed and massaged. Nipple fluid will be aspirated by a 
hand-held aspirator.  

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
17 
 
• 
MRI assessment of breast density. All MRI images will be acquired on a 3T MRI 
scanner located in the department of Radiology of the University of Arizona Medical 
center. Fat-water imaging will be performed using the radial Gradient-Echo and Spin-
Echo (GRASE) technique developed by co-investigator, Dr. Altbach (114). Women 
who cannot fit into the MRI scanner due to the large body size will continue the study 
and undergo all other study procedures.  
• 
Optional core needle biopsy. For participants who consent to this optional procedure, 
the medical specialist will use a 14-gauge needle under the ultrasound guidance to 
obtain up to 8 tissue cores from one of the breasts.      
 
Following completion of baseline evaluation, participants will be randomized to receive 
metformin or placebo for 12 months. Participants will receive a supply of study medication. 
Participants will be asked to take one 850 mg metformin or one placebo tablet daily with a full 8 
oz glass of water with a meal for the first four weeks, then two 850 mg metformin or two placebo 
tablets daily with meals for the remainder of the study. The same starting dose and gradual 
dose escalation up to 2,000 mg per day is used to minimize gastrointestinal symptoms for 
glycemic control in diabetics (GLUCOPHAGE prescribing information).  
 
Participants will be asked to keep an adverse event diary and menstrual calendar 
throughout the study.  In addition, participants will be provided with an intake calendar for 
recording medication usage. Study personnel will contact study participants within a week after 
study agent has been initiated and within a week following scheduled dose increase to assess 
compliance and any potential problems. 
 
Participants will return to the clinic at month 3 (13 ± 2 wks) to undergo the following 
procedures: 
• 
Collection of urine for urine pregnancy test. 
• 
Vital signs. 
• 
Update information on menstrual cycles.  
• 
Update medication usage. 
• 
Side effect evaluation. 
 
Participants will return at month 6 (26 ± 4 wks) to undergo the following procedures: 
• 
Collection of urine for urine pregnancy test and research tests. 
• 
Vital signs. 
• 
Update information on menstrual patterns/cycles.  
• 
Update medication usage. 
• 
Side effect evaluation. 
• 
Return unused pills. 
• 
Receive a new supply of study medication. 
• 
Collection of wt, waist circumference, waist-hip ratio measurements. 
• 
Collection of a fasting blood and NAF sample for research biomarkers. 
• 
MRI assessment of the breast. Women who cannot fit into the MRI scanner due to 
the large body size will not undergo the MRI assessment. 
• 
Optional breast core biopsy. 
 
When feasible, the month 6 procedures will be scheduled in the midluteal phase of the 
menstrual cycle. 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
18 
 
 
Participants will return to the clinic at month 9 (39 ± 2 wks) after initiation of agent 
intervention to undergo the following procedures: 
• 
Collection of urine for urine pregnancy test. 
• 
Vital signs. 
• 
Update information on menstrual patterns/cycles.  
• 
Update medication usage.  
• 
Side effect evaluation. 
Study personnel will contact study participants at least once and as needed between clinic visits 
to assess compliance and any potential problems. 
 
7.4 
Evaluations at Completion of Study Intervention 
At the end of the 12-month agent intervention (52 ± 4 wks), participants will return to the 
clinic to undergo the following procedures: 
  
• 
Collection of urine for urine pregnancy test and research tests. 
• 
Vital signs. 
• 
Update information on menstrual patterns/cycles.  
• 
Update medication usage.  
• 
Return unused drugs.  
• 
Side effects evaluation. 
• 
Anthropometric measurements including wt, waist circumference, waist-hip ratio. 
• 
A fasting blood for CBC/CMP/lipids and research biomarkers.     
• 
NAF collection.   
• 
MRI assessment of breast density. Women who cannot fit into the MRI scanner due 
to the large body size will not undergo the MRI assessment. 
• 
Completion of AFFQ and AAFQ.  
 
When feasible, the month 12 procedures will be scheduled in the midluteal phase of the 
menstrual cycle. 
 
Participants will be instructed to take the study agent until the day of the last study 
procedure. 
 
7.5 
Post-intervention Follow-up Period 
Following the study intervention, participants will be followed for 2 weeks for any adverse 
reactions.      
 
8. 
SPECIMEN MANAGEMENT  
 
8.1  
Collection and Handling Procedures 
 
Blood Samples 
Clinical labs 
Fasting blood samples will be collected during screening and at the end of intervention 
for CBC with differentials, and CMP/lipids.  FSH and/or estradiol will be done at screening for 
women with unknown menopausal status. Approximately 15 ml of blood will be drawn to one 3-5 
ml EDTA and one 7-10 ml SST or tiger top Vacutainer tubes as directed by the clinical lab, and 
labeled with the subject name.  Samples will be processed and stored according the standard 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
19 
 
protocol for each.  The serum tube (SST or tiger top for CMP) will be allowed to clot for 
approximately 30 minutes at room temperature then centrifuged within 1 hour of collection for 
serum separation.  The EDTA tube (for CBC/diff) will be gently inverted to mix for 
anticoagulation.  All samples will be stored under refrigeration prior to transfer to the commercial 
laboratory facility on the same day as obtained with a completed lab requisition. 
 
Research biomarkers 
Fasting blood samples will also be collected during baseline, month 6 and at the end of 
intervention for research biomarker analyses.  Approximately 30 ml of fasting blood will be 
drawn into two 10 ml SST or tiger top Vacutainer tubes and one 10 ml heparin Vacutainer tube.  
The blood in the SST or tiger top tubes will be allowed to clot for approximately 30 minutes at 
room temperature then centrifuged for serum separation. The heparin tube will be gently 
inverted to mix for anticoagulation.  Serum from the SST tubes will be aliquoted into 10 x 1-2 ml 
cryovials and plasma from the heparin tube will be aliquoted into 5 x 1-2 ml cryovials.  Samples 
will be labeled with the study ID, subject ID, and date of collection and stored at -80°C until 
analyses. 
 
NAF will be collected at baseline, month 6 and at the end of intervention. NAF will be 
collected in small capillary tubes. The capillary tubes will then be stored in a 5 ml cyrotube. 
Cryotubes will be labeled with the study ID, subject ID, and date of collection and stored at -
80°C until analyses. 
 
Clean catch urine will be collected at baseline, month 6 and at the end of intervention. 
Urine will be aliquoted into 4 x 1-2 ml cryovials. Cryovials will be labeled with the study ID, 
subject ID, and date of collection and stored at -80°C until analyses. 
 
Breast Biopsies 
Optional breast biopsies will be performed at baseline and month 6. Up to eight tissue 
cores will be collected at each procedure. Half of the tissue will be immediately fixed in 10% 
neutral buffered formalin for 24 hours, and then transferred to 70% ethanol prior to routine 
processing and paraffin embedding (FFPE). Representative FFPE specimens will be reviewed 
by UAMC pathology department. The remaining half will be placed in cryogenic vials or bags 
and flash frozen in liquid nitrogen and then stored at -80°C for future studies.  Samples will be 
labeled with the study ID, subject ID, and date of collection. 
  
8.2   
Shipping instructions 
Research specimens will be hand delivered to Dr. Sherry Chow’s laboratory for final 
storage and analyses.  Serum/plasma and frozen tissue will be delivered on dry ice. Paraffin-
embedded tissue blocks will be delivered at room temperature.  Each delivery is to be 
accompanied with a sample list which is to be signed by the senders and recipients.  The 
recipients will be instructed to return a copy of the signed receipt to the senders.  The delivery 
address is listed below. 
 
Catherine Cordova c/o Chow Laboratory 
Arizona Cancer Center, Room 4971 
1515 N. Campbell Ave. 
Tucson, AZ 85724 
Phone: (520) 626-5433 
ccordova@uacc.arizona.edu  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
8.3   
Tissue Banking 
Biological specimens collected for this study that are not expended in analyses 
described in this protocol may be retained (“banked”) for future research testing only with the 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
20 
 
consent of the subject.  With that consent, remaining serum/plasma and frozen tissue will be 
stored at -80°C for future testing; paraffin embedded tissue will be stored in locked cabinets at 
room temperature.  A log will be kept for all stored specimens regarding the date of collection, 
subjection identification number, study number, and the storage location.   
9. 
STATISTICAL CONSIDERATIONS 
 
9.1 
Analysis Plan 
The primary study endpoint is to compare the change in breast density as measured by 
FWR-MRI (when measured at baseline, 6 and 12 months) between metformin and placebo 
groups. Additional endpoints such as systemic hormone and cytokines, body weight, waist 
circumference, and waist-hip ratio will be measured at baseline, 6 and 12 months. Analysis for 
all study endpoints will be based on a linear mixed-effects model for the observed values across 
time, to adjust for the correlation among measurements within the same woman. The main 
effects in the model will be time (0, 6, 12), treatment group (metformin versus placebo), and the 
interaction between time and treatment group. The time parameter tests if there is a change 
among placebo treated women, while the group-by-time interaction tests if the change in 
metformin treated women differs from that in the placebo group. We expect that a simpler 
covariance structure, such as compound symmetry, will be adequate for repeated 
measurements within the same woman (since the measurements are equally spaced). 
Alternatively, we will compare correlation structures for the longitudinal measurements using 
Akaike’s information criterion.  All endpoints will be first assessed for normality, and 
transformations (such as a logarithmic transformation) will be used as necessary to reduce 
skewness prior to statistical analysis.   
 
Secondary analyses will assess whether differences in the changes in FWR-MRI 
between the metformin and placebo groups remain after adjustment for potential explanatory 
variables, such as changes in body weight, systemic hormones, and cytokines.  These 
explanatory variables will be added as independent predictors in the linear mixed-effects 
models.  These analyses will be restricted to explanatory variables that have demonstrated 
statistically significant metformin effects across time. 
 
For the metabolomic aim, pre- to post-intervention changes in all detectable compounds 
of known identify (currently comprising 397 biochemicals using the standard platforms offered 
by Metabolon, Inc) will be determined and compared between treatment groups using a two-
sample t-test. An estimate of the false discovery rate (q-value) will be calculated (115) to take 
into account the multiple comparisons that normally occur in metabolomic-based studies. A low 
q-value (q≤0.10) is an indication of high confidence in a result. While a higher q-value indicates 
diminished confidence, it does not necessarily rule out the significance of a result. Other lines of 
evidence may be taken into consideration when determining whether a result merits further 
scrutiny.  Such evidence may include a) significance in another dimension of the study, b) 
inclusion in a common pathway with a highly significant compound, or c) residing in a similar 
functional biochemical family with other significant compounds.   
 
Exploratory analyses will assess whether the observed metformin-induced changes in 
metabolite features are correlated with changes in FWR-MRI, body weight/composition, 
systemic hormones, and cytokines. The correlation will be estimated using a Pearson 
correlation coefficient. It is expected that any changes in these variables in the placebo group 
will reflect random variation only.  Thus, these analyses will be restricted to the metformin group 
to overcome dilution of the potential correlations by individuals in the placebo group.   
 
Exploratory analyses also will explore the correlation between baseline metabolite 
features and FWR-MRI, systemic hormones, and cytokines.  These analyses will be restricted to 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
21 
 
the metabolite features that are members of a common pathway to reduce the potential for an 
inflated alpha level. 
 
9.2 
Sample Size Justification 
Our sample size ensures adequate power to test all primary specific aims. We assume 
an initial sample size of 75 women per arm and allow the possibility of up to 20% dropout for the 
12-month follow-up measurement. This results in at least 60 evaluable women per group. To 
justify the sample size, we use the simplified comparison of change between 12 months versus 
baseline (ignoring the 6 month measurement).  For the FWR-MRI-derived change in breast 
density, we will be able to detect a decrease of 0.516 standard deviation (SD) units in the 
metformin treated women with 80% statistical power, assuming a two-sided α of 0.05. To 
estimate what this change would be in relation to breast density, we used the relationship 
between breast density and log(Fra50) based on our previous data.  Based on an analysis of 
our cross-sectional data, the estimated SD of log(Fra50) is 2.40. Thus, a decrease of 0.516 SD 
units corresponds to a change of -1.2384 (-0.516*2.40). Based on the regression line, this is 
equivalent to a 10% decrease in breast density as determined by standard mammography. For 
the additional primary outcomes (such as systemic hormones, cytokines, and weight), we will be 
able to detect a difference of 0.516 SD units with 80% statistical power, assuming a sample size 
of 60 evaluable women per group.  Based on our previous experience, we anticipate that 65% 
of the proposed cohort will provide sufficient NAF for metabolomic analysis, which results in 39 
women per group (allowing for up to 20% drop-out).  This will allow us to detect a difference of 
0.643 SD units with 80% statistical power. 
 
9.3 
Interim Analysis 
No formal interim statistical analyses are planned for this Phase II trial. Accrual, data 
collection, and any adverse events will be monitored on a regular basis. 
 
10. 
Data and Safety Monitoring Plan 
 
10.1  Protocol Risk Level   
This trial has been designated as a medium risk study.  Medium risk studies are 
intended to include all trials involving therapeutic intervention(s), which are not designated as 
high risk per NCI and the IND is not held by the investigator.  
 
10.2  Identification of the DSMB Obligated for Oversight Responsibilities  
The University of Arizona Cancer Center Data and Safety Monitoring Board (DSMB) will 
provide ongoing oversight for this trial semi-annually.   
 
10.3  Identification of the Entity Obligated for Routine Monitoring Duties  
Routine monitoring will be provided by the Quality Assurance/Quality Control (QA/QC) 
Program to ensure that the investigation is conducted according to protocol design and 
regulatory requirements.  
 
10.4  Monitoring Progress and Data Review Process 
Routine monitoring of participant data will be conducted at least every 6 months. 
The first routine monitoring visit will include at a minimum: 
 
 
Informed consent – 100% of cases enrolled;  
 
 
Participant eligibility - 50% of cases, up to two participants; 
 
 
Data review - 50% of cases, up to two participants. 
 
All subsequent monitoring visits will consist of randomly selected participant cases 
based on current enrollment and include continuing review of previously selected cases, as 
applicable.  A monitoring visit report and follow-up letter will be completed within approximately 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
22 
 
two weeks of the routine monitoring visit; a copy will be maintained in the study file. A 
query/finding form or an electronic record will also be completed by the monitor to request 
additional source documentation, clarification, information or corrections to the CRF and/or 
regulatory records. The study coordinator or other applicable staff responsible for the study will 
be given a copy of this form or will be notified of the electronic record for resolution of 
queries/findings. The query/finding form will be maintained with a copy of the visit report for 
follow-up at the next monitoring visit.  
 
 
The Principal Investigator will ensure the accuracy, completeness, legibility and 
timeliness of the data reported in the Case Report Form (CRF), or other acceptable data 
formats. Source documentation supporting the study data should indicate the participant’s 
participation in the trial and should document the dates and details of study procedures, adverse 
events, and participant status. CRFs should be completed via the institutional database or other 
acceptable data formats. Trials using paper CRFs will have data entered with a black ball-point 
pen or typed. Corrections to the forms should not obscure the original entry and should be made 
by striking the incorrect information with a single line. Each strike should be accompanied by the 
initials of the corrector and the correction date. All participant forms and study files will be stored 
in a secure area limited to authorized staff. Note: Routine monitoring of regulatory documents 
and test article will be conducted at least annually. A process is in place to implement study 
closure when significant risks or benefits are identified. 
 
11. 
Description and Reporting of Adverse Events 
 
11.1   Adverse Events  
An adverse event (AE) is any untoward medical occurrence in a study participant.  An 
AE does not necessarily have a causal relationship with the treatment or study participant.  An 
AE can therefore be any unfavorable and unintended sign (including a clinically significant 
abnormal laboratory finding), symptom, or disease temporally associated with participation in a 
study, whether or not related to that participation.  This includes all deaths that occur while a 
participant is on a study. 
 
A list of adverse events that have occurred or might occur (Reported Adverse Events 
and Potential Risks) can be found in Section 6.2, Pharmaceutical Information as well as the 
package insert.   
 
All adverse events that occur after the informed consent is signed must be recorded 
whether or not related to study agent. All adverse events will be entered into the OnCore 
database.  
 
AE Data Elements include: 
• 
AE reported date 
• 
AE Verbatim Term 
• 
Common Terminology Criteria for Adverse Events v4.0 (CTCAE) AE term 
• 
Event onset date and event ended date 
• 
Severity grade 
• 
Attribution to study agent (relatedness) 
• 
Whether or not the event was reported as a Serious Adverse Event (SAE) 
• 
Whether or not the subject dropped due to the event 
• 
Action taken with the study agent 
• 
Outcome of the event 
• 
Comments 
 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
23 
 
All AEs will be assessed according CTCAE Version 4 
(http://ctep.cancer.gov/protocolDevelopment/electronicapplications/docs/ctcaev4.pdf).  
 
AEs that do not have a corresponding CTCAE term will be assessed according to the 
general guidelines for grading used in the CTCAE v4.0 as stated below.  
 
Grade 
Severity 
Description  
1 
Mild 
Mild; asymptomatic or mild symptoms; clinical or 
diagnostic observations only; intervention not indicated. 
2 
Moderate 
Moderate; minimal, local or noninvasive intervention 
indicated; 
limiting age-appropriate instrumental ADL*. 
3 
Severe 
Severe or medically significant but not immediately life-
threatening; 
hospitalization or prolongation of hospitalization 
indicated; disabling; limiting self care ADL**. 
4 
Life threatening 
Life-threatening consequences; urgent intervention 
indicated. 
5 
Fatal 
Death related to AE. 
   
 Activities of Daily Living (ADL) 
*Instrumental ADL refer to preparing meals, shopping for groceries or clothes, using the 
telephone, managing money, etc. 
**Self care ADL refer to bathing, dressing and undressing, feeding self, using the toilet, 
taking medications, and not bedridden. 
 
The possibility that the adverse event is related to study agent will be classified as one of 
the following:  not related, unlikely, possible, probable, definite. 
  
All AEs, including lab abnormalities that in the opinion of the investigator are clinically 
significant, will be followed according to good medical practices and documented as such. 
 
11.2  Serious Adverse Events  
ICH Guideline E2A and Fed. Reg. 75,Sept. 29, 2010 define serious adverse events as 
those events, occurring at any dose, which meet any of the following criteria: 
• Results in death 
• Is life threatening (Note: the term life-threatening refers to an event in which the patient 
was at risk of death at the time of the event; it does not refer to an event which 
hypothetically might have caused death if it were more severe). 
• Requires inpatient hospitalization or prolongation of existing hospitalization 
• Results in persistent or significant incapacity or substantial disruption of the ability to 
conduct normal life functions. 
• Is a congenital abnormality/birth defect 
• Important medical events that may not result in death, be life-threatening or require 
hospitalization may be considered serious when, based upon appropriate medical 
judgment, they may jeopardize the patient or subject and may require medical or 
surgical intervention to prevent one of the outcomes listed. 
 
Note: A SAE may also be an important medical event, in the view of the investigator that 
requires medical or surgical intervention to prevent one of the outcomes listed above.  
 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
24 
 
All serious adverse events, regardless of attribution, and any deaths will be reported 
within 24 hours of notification of the event to the DSMB Coordinator. All SAEs which meet the 
criteria for a reportable event, as defined below, will be reported to the University of Arizona 
Human Subjects Protection Program (HSPP) within 10 working days of the event date or receipt 
of notification of the event. 
 
Reportable events must meet all three of the following criteria: 
• 
Unanticipated or unexpected in nature, frequency or severity, AND 
• 
Related or possibly related to participation in the research (there is a reasonable 
possibility that it is related), AND 
• 
The event suggests that the research places participants or others at a greater risk of 
harm than was previously known or recognized (not already referenced in existing 
study documents, such as the protocol, consent form or package insert). 
 
All serious adverse events will be processed by the DSMB Coordinator monthly for initial 
trend analysis and fully reviewed by the DSMB, every six months. The DSMB coordinator will 
review the SAE reporting process to confirm reporting requirements are met.   
 
11.3  Plan for assuring data accuracy and protocol compliance  
Routine study activity and safety information will be reported to the DSMB every six 
months, or more frequently if requested. These reports will include: 
 
• 
Study activity, cumulative and for the period under review; 
• 
Safety (narrative description on non-serious and serious adverse events); 
• 
Predetermined protocol early stopping rules for efficacy/futility;    
• 
Monitoring and protocol compliance; 
• 
Comments; 
• 
Attachments (AE data reviewed by the PI to compile the report, SAE 
letters and reports, results of any review(s), applicable correspondence 
with the HSPP or other regulatory agencies).  
 
Data, safety and study progress will be reported to HSPP at least annually and funding 
agency, as applicable. The PI will immediately notify; in writing, the funding agency, if 
applicable, any action resulting in a temporary or permanent suspension of the study. 
 
11.4 
Process to implement study closure when significant risks or benefits are 
identified 
 
There will be no formal stopping criteria. However, if periodic review performed by the 
UACC DSMB identified patterns of significant risks, a discussion of more frequent monitoring or 
early closure will be conducted between DSMB and the investigators. 
 
12. 
Regulatory Considerations 
 
12.1  Regulatory Board Review  
The study protocol will be activated after review and approval by the University of 
Arizona Cancer Center Scientific Review Committee and the University of Arizona HSPP. 
Approval of this protocol by the HSPP will also include approval of the protocol consenting 
document, or Informed Consent Form (ICF) and the accompanying HIPAA consenting 
instrument.  
 
12.2  Compliance with Protocol and Protocol Revisions 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
25 
 
Study personnel will conduct the study as described in this protocol. Any protocol 
revisions made in amendments to the protocol will be approved by the HSPP prior to 
implementation, except where necessary to avoid imminent hazard to a study participant.  If an 
amendment alters the study design or increases the potential risk to the participant, the ICF will 
be revised and submitted for approval to the HSPP. The revised ICF will be used to obtain 
consent from participants currently enrolled in the study or after withdrawal from the study if they 
are affected by the Amendment.   
 
12.3  Participant Informed Consent  
All study participants will sign the most current ICF that has been approved by the HSPP 
prior to enrollment on the study. Investigators will have ensured that participants are clearly and 
fully informed about the purpose, potential risks and any other critical issues regarding this 
clinical trial. 
 
12.4  Data Management and Safety Monitoring 
Participant safety and data integrity will be monitored by the UACC Data and Safety 
Monitoring Board in conjunction with the Quality Assurance/Quality Control Program (QA/QC). 
All participants registered to this study will be entered into the UACC database (OnCore) for 
accrual and treatment status tracking. Verification of consent, date of consent, and other 
relevant registration data will be tracked in OnCore. All adverse events will be entered into the 
OnCore database. All participant study files will be stored in a secure area limited to authorized 
staff. 
 
The Principal Investigator will ensure the accuracy, completeness and timeliness of the 
data reported. Source documentation supporting the reported data should indicate the 
participant’s participation in the trial and should document the dates and details of study 
procedures, adverse events, and participant status.  
 
  
 
 
 
 
13. 
Financing, Expenses, and/or Insurance 
Study procedures performed during study visits will be covered by the study budget.  
Research tests, including serum and tissue biomarker evaluations, will not be billed to the 
subject.  Subjects may incur minimal out-of-pocket expenses for transportation but will not be 
charged for study agent or any study-related activities.  Subjects will receive monetary 
compensation which they may use at their discretion for out of pocket cost such as 
transportation.  If injury occurs, medical care will be provided and charged to the subject’s 
insurer.   
 
 
 
References 
 
1. 
Flegal KM, Carroll MD, Kit BK, Ogden CL. Prevalence of obesity and trends in the distribution of body 
mass index among US adults, 1999-2010. JAMA 2012;307: 491-7. 
2. 
Li CI, Malone KE, Daling JR. Interactions between body mass index and hormone therapy and 
postmenopausal breast cancer risk (United States). Cancer Causes Control 2006;17: 695-703. 
3. 
Hunter DJ, Willett WC. Diet, body size, and breast cancer. Epidemiol Rev 1993;15: 110-32. 
4. 
Kaaks R, Van Noord PA, Den Tonkelaar I, Peeters PH, Riboli E, Grobbee DE. Breast-cancer incidence in 
relation to height, weight and body-fat distribution in the Dutch "DOM" cohort. Int J Cancer 1998;76: 647-51. 
5. 
van den Brandt PA, Spiegelman D, Yaun SS, et al. Pooled analysis of prospective cohort studies on height, 
weight, and breast cancer risk. Am J Epidemiol 2000;152: 514-27. 
6. 
Palomba S, Falbo A, Zullo F, Orio F, Jr. Evidence-based and potential benefits of metformin in the 
polycystic ovary syndrome: a comprehensive review. Endocr Rev 2009;30: 1-50. 
7. 
De Leo V, La Marca A, Orvieto R, Morgante G. Effect of metformin on insulin-like growth factor (IGF) I 
and IGF-binding protein I in polycystic ovary syndrome. J Clin Endocrinol Metab 2000;85: 1598-600. 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
26 
 
8. 
Pawelczyk L, Spaczynski RZ, Banaszewska B, Duleba AJ. Metformin therapy increases insulin-like 
growth factor binding protein-1 in hyperinsulinemic women with polycystic ovary syndrome. Eur J Obstet Gynecol 
Reprod Biol 2004;113: 209-13. 
9. 
Diamanti-Kandarakis E, Kouli C, Tsianateli T, Bergiele A. Therapeutic effects of metformin on insulin 
resistance and hyperandrogenism in polycystic ovary syndrome. Eur J Endocrinol 1998;138: 269-74. 
10. 
Moghetti P, Castello R, Negri C, et al. Metformin effects on clinical features, endocrine and metabolic 
profiles, and insulin sensitivity in polycystic ovary syndrome: a randomized, double-blind, placebo-controlled 6-
month trial, followed by open, long-term clinical evaluation. J Clin Endocrinol Metab 2000;85: 139-46. 
11. 
Goodwin PJ, Pritchard KI, Ennis M, Clemons M, Graham M, Fantus IG. Insulin-lowering effects of 
metformin in women with early breast cancer. Clin Breast Cancer 2008;8: 501-5. 
12. 
Sharma PK, Bhansali A, Sialy R, Malhotra S, Pandhi P. Effects of pioglitazone and metformin on plasma 
adiponectin in newly detected type 2 diabetes mellitus. Clin Endocrinol (Oxf) 2006;65: 722-8. 
13. 
Adamia N, Virsaladze D, Charkviani N, Skhirtladze M, Khutsishvili M. Effect of metformin therapy on 
plasma adiponectin and leptin levels in obese and insulin resistant postmenopausal females with type 2 diabetes. 
Georgian Med News 2007: 52-5. 
14. 
Desilets AR, Dhakal-Karki S, Dunican KC. Role of metformin for weight management in patients without 
type 2 diabetes. Ann Pharmacother 2008;42: 817-26. 
15. 
Zakikhani M, Dowling RJ, Sonenberg N, Pollak MN. The effects of adiponectin and metformin on prostate 
and colon neoplasia involve activation of AMP-activated protein kinase. Cancer Prev Res (Phila) 2008;1: 369-75. 
16. 
Phoenix KN, Vumbaca F, Claffey KP. Therapeutic metformin/AMPK activation promotes the angiogenic 
phenotype in the ERalpha negative MDA-MB-435 breast cancer model. Breast Cancer Res Treat 2009;113: 101-11. 
17. 
Liu B, Fan Z, Edgerton SM, et al. Metformin induces unique biological and molecular responses in triple 
negative breast cancer cells. Cell Cycle 2009;8: 2031-40. 
18. 
Zhu Z, Jiang W, Thompson MD, McGinley JN, Thompson HJ. Metformin as an energy restriction mimetic 
agent for breast cancer prevention. J Carcinog 2011;10: 17. 
19. 
Evans JM, Donnelly LA, Emslie-Smith AM, Alessi DR, Morris AD. Metformin and reduced risk of cancer 
in diabetic patients. BMJ 2005;330: 1304-5. 
20. 
Bowker SL, Majumdar SR, Veugelers P, Johnson JA. Increased cancer-related mortality for patients with 
type 2 diabetes who use sulfonylureas or insulin. Diabetes Care 2006;29: 254-8. 
21. 
Libby G, Donnelly LA, Donnan PT, Alessi DR, Morris AD, Evans JM. New users of metformin are at low 
risk of incident cancer: a cohort study among people with type 2 diabetes. Diabetes Care 2009;32: 1620-5. 
22. 
Currie CJ, Poole CD, Gale EA. The influence of glucose-lowering therapies on cancer risk in type 2 
diabetes. Diabetologia 2009;52: 1766-77. 
23. 
Bodmer M, Meier C, Krahenbuhl S, Jick SS, Meier CR. Long-term metformin use is associated with 
decreased risk of breast cancer. Diabetes Care 2010;33: 1304-8. 
24. 
Decensi A, Puntoni M, Goodwin P, et al. Metformin and cancer risk in diabetic patients: a systematic 
review and meta-analysis. Cancer Prev Res (Phila) 2010;3: 1451-61. 
25. 
Vona-Davis L, Rose DP. Type 2 diabetes and obesity metabolic interactions: common factors for breast 
cancer risk and novel approaches to prevention and therapy. Curr Diabetes Rev 2012;8: 116-30. 
26. 
Hadad S, Iwamoto T, Jordan L, et al. Evidence for biological effects of metformin in operable breast 
cancer: a pre-operative, window-of-opportunity, randomized trial. Breast Cancer Res Treat 2011;128: 783-94. 
27. 
Niraula S, Dowling RJ, Ennis M, et al. Metformin in early breast cancer: a prospective window of 
opportunity neoadjuvant study. Breast Cancer Res Treat 2012;135: 821-30. 
28. 
Bonanni B, Puntoni M, Cazzaniga M, et al. Dual effect of metformin on breast cancer proliferation in a 
randomized presurgical trial. J Clin Oncol 2012;30: 2593-600. 
29. 
Algire C, Amrein L, Bazile M, David S, Zakikhani M, Pollak M. Diet and tumor LKB1 expression interact 
to determine sensitivity to anti-neoplastic effects of metformin in vivo. Oncogene 2011;30: 1174-82. 
30. 
Phoenix KN, Vumbaca F, Fox MM, Evans R, Claffey KP. Dietary energy availability affects primary and 
metastatic breast cancer and metformin efficacy. Breast Cancer Res Treat 2010;123: 333-44. 
31. 
Cuzick J, Warwick J, Pinney E, Warren RM, Duffy SW. Tamoxifen and breast density in women at 
increased risk of breast cancer. J Natl Cancer Inst 2004;96: 621-8. 
32. 
McCormack VA, dos Santos Silva I. Breast density and parenchymal patterns as markers of breast cancer 
risk: a meta-analysis. Cancer Epidemiol Biomarkers Prev 2006;15: 1159-69. 
33. 
Boyd NF, Guo H, Martin LJ, et al. Mammographic density and the risk and detection of breast cancer. N 
Engl J Med 2007;356: 227-36. 
34. 
Warner E, Lockwood G, Tritchler D, Boyd NF. The risk of breast cancer associated with mammographic 
parenchymal patterns: a meta-analysis of the published literature to examine the effect of method of classification. 
Cancer Detect Prev 1992;16: 67-72. 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
27 
 
35. 
Boyd NF, Rommens JM, Vogt K, et al. Mammographic breast density as an intermediate phenotype for 
breast cancer. Lancet Oncol 2005;6: 798-808. 
36. 
Martin LJ, Boyd NF. Mammographic density. Potential mechanisms of breast cancer risk associated with 
mammographic density: hypotheses based on epidemiological evidence. Breast Cancer Res 2008;10: 201. 
37. 
Greendale GA, Reboussin BA, Slone S, Wasilauskas C, Pike MC, Ursin G. Postmenopausal hormone 
therapy and change in mammographic density. J Natl Cancer Inst 2003;95: 30-7. 
38. 
Stuedal A, Ma H, Bjorndal H, Ursin G. Postmenopausal hormone therapy with estradiol and norethisterone 
acetate and mammographic density: findings from a cross-sectional study among Norwegian women. Climacteric 
2009;12: 248-58. 
39. 
Atkinson C, Warren R, Bingham SA, Day NE. Mammographic patterns as a predictive biomarker of breast 
cancer risk: effect of tamoxifen. Cancer Epidemiol Biomarkers Prev 1999;8: 863-6. 
40. 
Decensi A, Robertson C, Guerrieri-Gonzaga A, et al. Randomized double-blind 2 x 2 trial of low-dose 
tamoxifen and fenretinide for breast cancer prevention in high-risk premenopausal women. J Clin Oncol 2009;27: 
3749-56. 
41. 
Yang WT, Lewis MT, Hess K, et al. Decreased TGFbeta signaling and increased COX2 expression in high 
risk women with increased mammographic breast density. Breast Cancer Res Treat 2010;119: 305-14. 
42. 
Li T, Sun L, Miller N, et al. The association of measured breast tissue characteristics with mammographic 
density and other risk factors for breast cancer. Cancer Epidemiol Biomarkers Prev 2005;14: 343-9. 
43. 
dos Santos Silva I, Johnson N, De Stavola B, et al. The insulin-like growth factor system and 
mammographic features in premenopausal and postmenopausal women. Cancer Epidemiol Biomarkers Prev 
2006;15: 449-55. 
44. 
Diorio C, Pollak M, Byrne C, et al. Insulin-like growth factor-I, IGF-binding protein-3, and mammographic 
breast density. Cancer Epidemiol Biomarkers Prev 2005;14: 1065-73. 
45. 
Knowler WC, Barrett-Connor E, Fowler SE, et al. Reduction in the incidence of type 2 diabetes with 
lifestyle intervention or metformin. N Engl J Med 2002;346: 393-403. 
46. 
DPP. The 10-year cost-effectiveness of lifestyle intervention or metformin for diabetes prevention. 
Diabetes Care 2012;35: 723-30. 
47. 
Kopans DB. Basic physics and doubts about relationship between mammographically determined tissue 
density and breast cancer risk. Radiology 2008;246: 348-53. 
48. 
Yaffe MJ. Mammographic density. Measurement of mammographic density. Breast Cancer Res 2008;10: 
209. 
49. 
Law J, Faulkner K. Cancers detected and induced, and associated risk and benefit, in a breast screening 
programme. Br J Radiol 2001;74: 1121-7. 
50. 
Stephenson GD, Rose DP. Breast cancer and obesity: an update. Nutr Cancer 2003;45: 1-16. 
51. 
Plymate SR, Matej LA, Jones RE, Friedl KE. Inhibition of sex hormone-binding globulin production in the 
human hepatoma (Hep G2) cell line by insulin and prolactin. J Clin Endocrinol Metab 1988;67: 460-4. 
52. 
Plymate SR, Jones RE, Matej LA, Friedl KE. Regulation of sex hormone binding globulin (SHBG) 
production in Hep G2 cells by insulin. Steroids 1988;52: 339-40. 
53. 
McTernan PG, Anwar A, Eggo MC, Barnett AH, Stewart PM, Kumar S. Gender differences in the 
regulation of P450 aromatase expression and activity in human adipose tissue. Int J Obes Relat Metab Disord 
2000;24: 875-81. 
54. 
Del Giudice ME, Fantus IG, Ezzat S, McKeown-Eyssen G, Page D, Goodwin PJ. Insulin and related 
factors in premenopausal breast cancer risk. Breast Cancer Res Treat 1998;47: 111-20. 
55. 
Hirose K, Toyama T, Iwata H, Takezaki T, Hamajima N, Tajima K. Insulin, insulin-like growth factor-I 
and breast cancer risk in Japanese women. Asian Pac J Cancer Prev 2003;4: 239-46. 
56. 
Gunter MJ, Hoover DR, Yu H, et al. Insulin, insulin-like growth factor-I, and risk of breast cancer in 
postmenopausal women. J Natl Cancer Inst 2009;101: 48-60. 
57. 
Kaaks R, Berrino F, Key T, et al. Serum sex steroids in premenopausal women and breast cancer risk 
within the European Prospective Investigation into Cancer and Nutrition (EPIC). J Natl Cancer Inst 2005;97: 755-
65. 
58. 
Micheli A, Muti P, Secreto G, et al. Endogenous sex hormones and subsequent breast cancer in 
premenopausal women. Int J Cancer 2004;112: 312-8. 
59. 
Thomas HV, Key TJ, Allen DS, et al. A prospective study of endogenous serum hormone concentrations 
and breast cancer risk in premenopausal women on the island of Guernsey. Br J Cancer 1997;75: 1075-9. 
60. 
Kabuto M, Akiba S, Stevens RG, Neriishi K, Land CE. A prospective study of estradiol and breast cancer 
in Japanese women. Cancer Epidemiol Biomarkers Prev 2000;9: 575-9. 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
28 
 
61. 
Rosenberg CR, Pasternack BS, Shore RE, Koenig KL, Toniolo PG. Premenopausal estradiol levels and the 
risk of breast cancer: a new method of controlling for day of the menstrual cycle. Am J Epidemiol 1994;140: 518-
25. 
62. 
Jones J, Clemmons D. Insulin-like growth factors and their binding proteins: biological actions. Endocrine 
Review 1995;16: 3-34. 
63. 
Schernhammer E, Holly J, Pollak M, Hankinson S. Circulating levels of insulin-like growth factors, their 
binding proteins, and breast cancer risk. Cancer Epidemiology, Biomarkers & Prevention 2005;14: 699-704. 
64. 
Allen N, Roddam A, Allen D, et al. A prospective study of serum insulin-like growth factor-1 (IGF-1), 
IGF-II, IGF-binding protein-3 and breast cancer risk. British Journal of Cancer 2005;92: 1283-7. 
65. 
Hankinson S, Schernhammer E. Insulin-like growth factor and breast cancer risk: evidence from 
observational studies. Breast Disease 2003;17: 27-40. 
66. 
Tessitore L, Vizio B, Jenkins O, et al. Leptin expression in colorectal and breast cancer patients. Int J Mol 
Med 2000;5: 421-6. 
67. 
Tessitore L, Vizio B, Pesola D, et al. Adipocyte expression and circulating levels of leptin increase in both 
gynaecological and breast cancer patients. Int J Oncol 2004;24: 1529-35. 
68. 
Han C, Zhang HT, Du L, et al. Serum levels of leptin, insulin, and lipids in relation to breast cancer in 
china. Endocrine 2005;26: 19-24. 
69. 
Miyoshi Y, Funahashi T, Tanaka S, et al. High expression of leptin receptor mRNA in breast cancer tissue 
predicts poor prognosis for patients with high, but not low, serum leptin levels. Int J Cancer 2006;118: 1414-9. 
70. 
Chen DC, Chung YF, Yeh YT, et al. Serum adiponectin and leptin levels in Taiwanese breast cancer 
patients. Cancer Lett 2006;237: 109-14. 
71. 
Mantzoros CS, Bolhke K, Moschos S, Cramer DW. Leptin in relation to carcinoma in situ of the breast: a 
study of pre-menopausal cases and controls. Int J Cancer 1999;80: 523-6. 
72. 
Coskun U, Gunel N, Toruner FB, et al. Serum leptin, prolactin and vascular endothelial growth factor 
(VEGF) levels in patients with breast cancer. Neoplasma 2003;50: 41-6. 
73. 
Sauter ER, Garofalo C, Hewett J, Hewett JE, Morelli C, Surmacz E. Leptin expression in breast nipple 
aspirate fluid (NAF) and serum is influenced by body mass index (BMI) but not by the presence of breast cancer. 
Horm Metab Res 2004;36: 336-40. 
74. 
Chu NF, Makowski L, Hotamisligil GS, Rimm EB. Stability of human plasma leptin concentrations within 
36 hours following specimen collection. Clin Biochem 1999;32: 87-9. 
75. 
Groschl M, Wagner R, Dorr HG, Blum W, Rascher W, Dotsch J. Variability of leptin values measured 
from different sample matrices. Horm Res 2000;54: 26-31. 
76. 
Klein S, Coppack SW, Mohamed-Ali V, Landt M. Adipose tissue leptin production and plasma leptin 
kinetics in humans. Diabetes 1996;45: 984-7. 
77. 
Thomas T, Burguera B, Melton LJ, 3rd, et al. Relationship of serum leptin levels with body composition 
and sex steroid and insulin levels in men and women. Metabolism 2000;49: 1278-84. 
78. 
Hu X, Juneja SC, Maihle NJ, Cleary MP. Leptin--a growth factor in normal and malignant breast cells and 
for normal mammary gland development.[see comment]. J Natl Cancer Inst 2002;94: 1704-11. 
79. 
Somasundar P, Yu AK, Vona-Davis L, McFadden DW. Differential effects of leptin on cancer in vitro. J 
Surg Res 2003;113: 50-5. 
80. 
Saxena NK, Vertino PM, Anania FA, Sharma D. leptin-induced growth stimulation of breast cancer cells 
involves recruitment of histone acetyltransferases and mediator complex to CYCLIN D1 promoter via activation of 
Stat3. J Biol Chem 2007;282: 13316-25. 
81. 
Yin N, Wang D, Zhang H, et al. Molecular mechanisms involved in the growth stimulation of breast cancer 
cells by leptin. Cancer Res 2004;64: 5870-5. 
82. 
Dieudonne MN, Machinal-Quelin F, Serazin-Leroy V, Leneveu MC, Pecquery R, Giudicelli Y. Leptin 
mediates a proliferative response in human MCF7 breast cancer cells. Biochem Biophys Res Commun 2002;293: 
622-8. 
83. 
Castellucci M, De Matteis R, Meisser A, et al. Leptin modulates extracellular matrix molecules and 
metalloproteinases: possible implications for trophoblast invasion. Mol Hum Reprod 2000;6: 951-8. 
84. 
Rose DP, Gilhooly EM, Nixon DW. Adverse effects of obesity on breast cancer prognosis, and the 
biological actions of leptin (review). Int J Oncol 2002;21: 1285-92. 
85. 
Sierra-Honigmann MR, Nath AK, Murakami C, et al. Biological action of leptin as an angiogenic 
factor.[see comment]. Science 1998;281: 1683-6. 
86. 
Fischer S, Hanefeld M, Haffner SM, et al. Insulin-resistant patients with type 2 diabetes mellitus have 
higher serum leptin levels independently of body fat mass. Acta Diabetologica 2002;39: 105-10. 
87. 
Wauters M, Considine RV, Yudkin JS, Peiffer F, De Leeuw I, Van Gaal LF. Leptin levels in type 2 
diabetes: associations with measures of insulin resistance and insulin secretion. Horm Metab Res 2003;35: 92-6. 

 
 
UA Project No. 1300000596 
                                                                                                                   Protocol Version 11, 10/4/2016 
 
29 
 
88. 
Leyva F, Anker SD, Egerer K, Stevenson JC, Kox WJ, Coats AJ. Hyperleptinaemia in chronic heart failure. 
Relationships with insulin.[see comment]. Eur Heart J 1998;19: 1547-51. 
89. 
Matsubara M, Maruoka S, Katayose S. Inverse relationship between plasma adiponectin and leptin 
concentrations in normal-weight and obese women. Eur J Endocrinol 2002;147: 173-80. 
90. 
Yang WS, Lee WJ, Funahashi T, et al. Weight reduction increases plasma levels of an adipose-derived 
anti-inflammatory protein, adiponectin.[erratum appears in J Clin Endocrinol Metab 2002 Apr;87(4):1626]. J Clin 
Endocrinol Metab 2001;86: 3815-9. 
91. 
Stefan N, Stumvoll M. Adiponectin--its role in metabolism and beyond. Horm Metab Res 2002;34: 469-74. 
92. 
Kang JH, Lee YY, Yu BY, et al. Adiponectin induces growth arrest and apoptosis of MDA-MB-231 breast 
cancer cell. Arch Pharm Res 2005;28: 1263-9. 
93. 
Arditi JD, Venihaki M, Karalis KP, Chrousos GP. Antiproliferative effect of adiponectin on MCF7 breast 
cancer cells: a potential hormonal link between obesity and cancer. Horm Metab Res 2007;39: 9-13. 
94. 
Brakenhielm E, Veitonmaki N, Cao R, et al. Adiponectin-induced antiangiogenesis and antitumor activity 
involve caspase-mediated endothelial cell apoptosis. Proc Natl Acad Sci U S A 2004;101: 2476-81. 
95. 
Harvie M, Howell A, Vierkant RA, et al. Association of gain and loss of weight before and after 
menopause with risk of postmenopausal breast cancer in the Iowa women's health study. Cancer Epidemiol 
Biomarkers Prev 2005;14: 656-61. 
96. 
Muti P, Stanulla M, Micheli A, et al. Markers of insulin resistance and sex steroid hormone activity in 
relation to breast cancer risk: a prospective analysis of abdominal adiposity, sebum production, and hirsutism (Italy). 
Cancer Causes Control 2000;11: 721-30. 
97. 
Harris HR, Willett WC, Terry KL, Michels KB. Body fat distribution and risk of premenopausal breast 
cancer in the Nurses' Health Study II. J Natl Cancer Inst 2012;103: 273-8. 
98. 
Sonnenschein E, Toniolo P, Terry MB, et al. Body fat distribution and obesity in pre- and postmenopausal 
breast cancer. Int J Epidemiol 1999;28: 1026-31. 
99. 
Huang Z, Willett WC, Colditz GA, et al. Waist circumference, waist:hip ratio, and risk of breast cancer in 
the Nurses' Health Study. Am J Epidemiol 1999;150: 1316-24. 
100. 
Lindon JC, Holmes E, Nicholson JK. Metabonomics in pharmaceutical R&D. FEBS J 2007;274: 1140-51. 
101. 
Huo T, Cai S, Lu X, Sha Y, Yu M, Li F. Metabonomic study of biochemical changes in the serum of type 2 
diabetes mellitus patients after the treatment of metformin hydrochloride. J Pharm Biomed Anal 2009;49: 976-82. 
102. 
Thompson PA, Hsu CH, Green S, et al. Sulindac and sulindac metabolites in nipple aspirate fluid and effect 
on drug targets in a phase I trial. Cancer Prev Res (Phila) 2010;3: 101-7. 
103. 
Grundy SM, Cleeman JI, Daniels SR, et al. Diagnosis and management of the metabolic syndrome: an 
American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Circulation 2005;112: 
2735-52. 
104. 
Crofford OB. Metformin. N Engl J Med 1995;333: 588-9. 
105. 
Stumvoll M, Nurjhan N, Perriello G, Dailey G, Gerich JE. Metabolic effects of metformin in non-insulin-
dependent diabetes mellitus. N Engl J Med 1995;333: 550-4. 
106. 
Khan AY, Macaluso M, McHale RJ, Dahmen MM, Girrens K, Ali F. The adjunctive use of metformin to 
treat or prevent atypical antipsychotic-induced weight gain: a review. J Psychiatr Pract 2010;16: 289-96. 
107. 
Marchesini G, Brizi M, Bianchi G, Tomassetti S, Zoli M, Melchionda N. Metformin in non-alcoholic 
steatohepatitis. Lancet 2001;358: 893-4. 
108. 
Orchard TJ, Temprosa M, Goldberg R, et al. The effect of metformin and intensive lifestyle intervention on 
the metabolic syndrome: the Diabetes Prevention Program randomized trial. Ann Intern Med 2005;142: 611-9. 
109. 
Bolen S, Feldman L, Vassy J, et al. Systematic review: comparative effectiveness and safety of oral 
medications for type 2 diabetes mellitus. Ann Intern Med 2007;147: 386-99. 
110. 
de Jager J, Kooy A, Lehert P, et al. Long term treatment with metformin in patients with type 2 diabetes 
and risk of vitamin B-12 deficiency: randomised placebo controlled trial. BMJ 2010;340: c2181. 
111. 
Bailey CJ, Turner RC. Metformin. N Engl J Med 1996;334: 574-9. 
112. 
Salpeter SR, Greyber E, Pasternak GA, Salpeter EE. Risk of fatal and nonfatal lactic acidosis with 
metformin use in type 2 diabetes mellitus. Cochrane Database Syst Rev 2010: CD002967. 
113. 
Salpeter SR, Greyber E, Pasternak GA, Salpeter Posthumous EE. Risk of fatal and nonfatal lactic acidosis 
with metformin use in type 2 diabetes mellitus. Cochrane Database Syst Rev 2010: CD002967. 
114. 
Li Z, Gmitro AF, Bilgin A, Altbach MI. Fast decomposition of water and lipid using a GRASE technique 
with the IDEAL algorithm. Magn Reson Med 2007;57: 1047-57. 
115. 
Storey JD, Tibshirani R. Statistical significance for genomewide studies. Proc Natl Acad Sci U S A 
2003;100: 9440-5.