bluuebunny/crossref_metadata_2025 huggingface dataset:
P5-14-02: Clinicopathologic and Prognostic Difference of Screen Detected Breast Cancer Compared with Symptomatic Breast Cancer.
Authors: Kim J , Lee SK , Kim S , Koo MY , Choi M-Y , Cho DH , Bae SY , Lee J , Jung SP , Lee JE , Yang J-H , Nam SJ
Published: June 2012

Background: Breast cancer screening program makes it possible to detect early cancer, thus to reduce breast cancer mortality. The authors studied clinicopathologic characteristics and prognosis of screen detected invasive breast cancer compared with symptomatic breast cancer. Furthermore, we compared the result according to molecular subtypes (luminal A, luminal B, Her2, triple negative), so intended to identify the role of screening in each subtypes. Material and Methods: From January 2002 to June 2008, 3141 patients who underwent operation for the treatment of invasive ductal carcinoma(NOS) at Samsung medical center were included. Among them, 1025 patient were screen detected, 2116 patient were symptomatic, out of screening over 2 years. We reviewed the medical records retrospectively.

Result: Screen detected breast cancer was associated with older patients, smaller tumor size, more hormone receptor- positive, less lymph node involvement, lower stage and reduced mortality compared with symptomatic breast cancer (P < .001). According to the molecular subtype, in luminal A subtype, the result shows better pathologic feature and also favorable overall and recur-free survial significantly.

Conclusion: Compared to symptomatic breast cancer patients, screen detected breast cancer patients have favorable pathological and molecular characteristics, so better outcomes. According to the molecular subtype, only in luminal A subtype, screen detected breast cancer shows both overall and disease free survival benefit, and also acts as an independent prognostic factor itself. So, screening program seems to have a different efficacy depending on the molecular subtype of breast cancer

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-14-02.
P5-16-01: Are We Going To Be Able To Train Future Surgeons How To Perform Axillary Lymph Node Dissection?
Authors: Betambeau N , Chan C
Published: June 2012

Background: Axillary lymph node dissection (ALND) has been performed regularly by surgeons for several decades. The sentinel lymph node era has led to a reduction in ALND procedures as node negative women are now spared further surgery and morbidity. Following the publication of the ACOSOG Z0011 trial, it is conceivable that completion ALND (cALND) may be rendered unnecessary for many women who have breast conserving surgery and have 1 to 2 positive sentinel lymph node disease. If there is a substantial drop in ALND procedures, this may impact on our ability to train surgeons in the future.

Material and Methods: We retrospectively reviewed the breast cancer practice for 2 consultant surgeons in a busy UK centre. In this centre all patients with a positive diagnosis of invasive breast cancer had preoperative axillary ultrasound scanning (USS) and needle biopsy (fine needle aspiration or core biopsy) if enlarged or suspicious axillary lymph nodes were seen. Hence sentinel lymph node biopsy (SLNB) was only performed on patients with both clinically and radiologically negative axillary lymph nodes.

Results: In 2009 and 2010 the 2 consultants treated a total of 255 patients with invasive breast cancer. Thirty one patients (12.2%) had positive axillary lymph disease identified by USS and axillary needle biopsy; these women were treated with ALND. The remaining 224 patients had clinically and radiologically negative axillary lymph nodes and proceeded to SLNB. Of these, 58 patients had at least one positive sentinel lymph node (25.9%) and proceeded to cALND; 39 women had breast conserving surgery and 19 women had mastectomy. If our centre were to adopt a policy of observation only in those women having breast conserving surgery and whom had no more than 2 positive sentinel lymph nodes (as per ACOSOG Z0011 trial), then 33 fewer ALND would have been performed. This would leave a new total of 56 ALND procedures being performed over a 2 year period in women with pre-operatively identified positive axillary lymph nodes, those undergoing mastectomy and those women with 3 or greater positive sentinel lymph nodes on SLNB. On our service we have 2 residents which would result in a maximum number of 14 ALND procedures per year that each resident may be trained to perform. It is likely that the actual number will be less due to commitments away from the elective operating room, such as emergency duties and annual leave etc. Is this an adequate number of ALND procedures for a resident to gain competence in the technique?

Discussion: The training of surgical residents is competence based and if our centre is representative of most centres treating breast cancers in the UK, will the teaching of ALND procedures be limited to specialist, ultra-high volume centres if the ACOSOG Z0011 trial findings are to be adopted?

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-16-01.
P5-17-03: The Association between Breast Cancer Related Lymphedema's Risk Factors and Likelihood of Edema Progression.
Authors: Skolny MN , Miller CL , O'Toole J , Sadek B , Ancukiewicz M , Taghain AG
Published: June 2012

Purpose/Objective(s): Breast cancer related lymphedema (BCRL) is one of the most feared long term side effects of treatment. Although emergence of the sentinel lymph node biopsy (SLNB) has decreased the rate of BCRL, it continues to be an issue for this population. The goal of this study is to evaluate the prognostic risk factors for BCRL development and progression based on longitudinal prospective limb volume (LV) measurements and associated surgical, radiation and medical oncology factors.

Materials/Methods: Since 2005 newly diagnosed breast cancer (BC) patients were prospectively screen via perometery (Pero-System). For this analysis patients were required to have undergone at least four measurements and have at least 24 months of follow up to allow for adequate time for LE development. Bilateral pre-operative volume measurements of the upper extremity were compared to postoperative measurements and at 4 to 6 month intervals to assess for limb volume changes. At each time point (tx), relative volume change (RVC) of the treated arm was calculated using volume ratios of treated (T) to non-treated (N) side compared to the pre-operative baseline (t1) (RVC=(Ttx/Ntx)/(Tt1/Nt1)-1) as described in Ancukiewicz et al 2010. Our institution utilizes >5% RVC as an indicator of lymphedema. For this analysis, mild lymphedema was classified as a RVC of 5–9.9% and moderate lymphedema was classified as a RVC ≥ 10%. A univariate analysis was performed to identify risk factors and likelihood to LE progression.

Results: In a cohort of 415 women, 14.4 %(60) and 6.7% (28) developed mild and moderate BCRL, respectively. Twenty percent (14) and 75 %(21) of patients in the mild and moderate cohorts, respectively, had a persistent edema that was documented at a least 2 consecutive data points. Eighty percent (56) and 25% (7) of patients that had a documented incidence of an elevated RVC had returned below an RVC<5% and their subsequent visits. Based on Kendall's Tau P-value of <0.0001 persistent edemas were associated with axillary lymph node dissection (ALND), number of lymph nodes removed, axillary fields and dose of radiation.

Conclusion: Breast cancer related lymphedema is a feared long term side effects and negatively impacts the physical and psychological aspects of an individual's life. A condition that is considered manageable but not curable, it is essential providers identify high risk individuals. Establishing a a lymphedema screening program may identify early lymphedema which could be potentially be treated successfully.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-17-03.
P5-17-04: Association between Breast Cancer and Osteoporosis among Women 85 Years or Older.
Authors: Okanami Y , Honma N , Arai T , Sawabe M , Maeda I , Takagi M , Younes M , Takubo K
Published: June 2012

Background: The pathogenesis of breast cancer in very elderly women is of interest, because estrogen levels are likely to be extremely low during the development of the disease. Estrogens have opposing effects on the pathogenesis of breast cancer and osteoporosis. In an effort to understand the significance of estrogens in the pathogenesis of breast cancer in this group, we examined the association between breast cancer and osteoporosis in women at least 85 years old, taking body mass index (BMI) and hormone receptors status into consideration.

Methods:Clinical records of consecutive elderly women (≥ 85 y/o) who underwent breast cancer surgery at Tokyo Metropolitan Geriatric Hospital (BC) and control women of the same age group (Cont) were reviewed; osteoporosis and BMI status in both groups were recorded and compared. The status of estrogen receptor (ER) and progesterone receptor (PR) of breast cancers was examined immunohistochemically and compared between BC with and without osteoporosis (BC-OP and BC-nonOP, respectively).

Results:Frequency of osteoporosis was significantly lower among BC than Cont. There was no difference in BMI measured after 85 y/o between BC and Cont; however, percentage of women, whose BMI measured when they were in their sixties or seventies was ≥ 20% higher than BMI measured when they were 85 y/o or older, was significantly higher among BC than Cont (31% and 2%, respectively. P = 0.0001). ER positivity of breast cancer did not differ between BC-OP and BC-nonOP, whereas PR positivity was significantly higher among BC-nonOP than BC-OP (P = 0.0359).

Discussion: The inverse relationship between the incidence of breast cancer and osteoporosis suggests an important role for estrogens in the pathogenesis of breast cancer in the very elderly women. Our finding that one third of BC had ≥ 20% higher BMI when they were in their sixties or seventies suggests they may also had elevated serum estrogens during these earlier years, because increased BMI has been reported to be associated with increased serum estrogens in postmenopausal women. Expression of PR is regulated by estrogen-ER signaling, and PR positivity is considered to reflect the effectiveness of estrogen-ER pathway. Significant difference of PR positivity between BC-nonOP and BC-OP suggests the more importance of estrogens in BC-nonOP than BC-OP.

Conclusion:Estrogens seem to play an important role in the pathogenesis of breast cancers in very elderly women, especially without osteoporosis. With increasing aging population in developed countries, those findings may have implications for breast cancer prevention in this age group.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-17-04.
P5-19-06: Highly Effective of Gemcitabine and Cisplatin (GP) as First-Line Combination Therapy in Patients with Triple-Negative Metastatic Breast Cancer: Final Report of a Phase II Trial.
Authors: Wang Z , Hu X , Wang B , Wang L , Zhang J , Wang H , Liu G , Hu Z , Wu J , Shao Z
Published: June 2012

Background

Triple-negative breast cancer (TNBC) contributes to poor prognosis and there is no established standard chemotherapy this subtype of patients. It has been postulated that related cancers would confer sensitivity to certain cytotoxic agents like cisplatin. Cisplatin and gemcitabine have single-agent activity in metastatic breast cancer and preclinical data support synergy of the combination. The objective of this study was to evaluate doublet with gemcitabine/Cisplatin (GP) as first-line therapy in patients with metastatic TNBC.

Material and Methods: This is a prospective single-institutional, open-label, phase II trial. The primary endpoint was progression free survival (PFS). Eligible subjects were aging from 18 to 75 years old, with no prior chemotherpay for MBC, with tumors negative for ER, PR or HER2, with at least one measurable disease according to the RECIST criteria, with ECOG PS of 0–1, and with adequate organ function. All patients received 21-day cycles of gemcitabine 1,000mg/m2 on days 1 and 8 and cisplatin 25 mg/m2 on days 1 through 3. Treatment was continued until disease progression or unacceptable toxicity or up to 8 cycles. (ClinicalTrials.gov number, NCT00601159)

Results: A median age was 49 years (range: 29–74 years). 58 patients had received neo/adjuvant chemotherapy (53 patients with anthracycline and/or taxane). The median number of treatment cycles was six (range: 2–8 cycles). In 64 assessable patients, we observed 10 complete response (CR; 15.6%), 30 partial responses (PR; 46.9%), 17 patients (26.6%) with stable disease (SD), and 7 patients (10.9%) with progressive disease, for an overall response rate of 62.5% (95% CI, 50.3% to 74.7%)..*** The median PFS was 7.7 months (95% CI, 6.0 to 9.4). With a median follow-up time of 28 months, the median overall survival was 19.1 months (95% CI, 12.5 to 25.7). Grade 3 or 4 toxicities were neutropenia 42.2%, thrombocytopenia 29.7%, anemia 18.8%, nausea/vomiting 15.6%, fatigue 14.1%, constipation 3%, sensory neuropathy 1.6%, 2 patients developed febrile neutropenia. The chemotherapy doses were reduced in 13.3% (6 pts) because of toxicity. There were no treatment-related deaths.

Conclusion: Significant activity and favorable toxicity profile of GP regimen as first-line chemotherapy in patients with metastatic TNBC. It provided a basis for considering GP for further evaluation in phase III trials for women with metastatic TNBC in China. (ClinicalTrials. gov number, NCT01287624)

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-19-06.
P5-21-02: The Susan G. Komen for the Cure® Tissue Bank at the IU Simon Cancer Center: The Source for Normal Breast Tissue and Biospecimens.
Authors: Clare SE , Mathieson T , Henry JE , Zhang H , Way ES , Ridley KE , Badve S , Herbert B-S , Rufenbarger CA , Storniolo AMV
Published: June 2012

Background

Our efforts to prevent and treat breast cancer are significantly impeded by a lack of knowledge of the biology and developmental genetics of the normal mammary gland. This ignorance has been the consequence of the lack of access to richly annotated, high quality normal breast specimens. The Susan G. Komen for the Cure® Tissue Bank at the IU Simon Cancer Center (KTB) was established expressly to remedy this deficiency. The KTB is a repository of specimens from volunteer donors with no clinical evidence of breast malignancy. The Bank's mission is to make available specimens that will enable an understanding of the developmental biology of the normal breast, to provide insight into breast oncogenesis, and to provide a normal control for breast cancer research. The purpose of this presentation is to increase the awareness of this unique and rich research resource and to actively solicit the use of its specimens.

Methods: The KTB has been prospectively banking fresh frozen breast tissue since mid-2006. Coincident with the tissue donation two tubes of blood are obtained, which are processed for lymphocyte DNA, serum and plasma. These specimens are richly annotated with detailed information regarding the donors’ reproductive history, medical history, family history, and medications. Standard Operating Procedures have been constructed so as to control, limit and identify potential sources of bias. All of this information is recorded in an Oracle-based, searchable database.

Results: As of June 2011, the KTB and its predecessor bank, Mary Ellen's Bank, have available fresh frozen breast tissue (10 gauge cores) from 1469 donors; formalin-fixed, paraffin-embedded tissue from 1055; DNA from 7507; serum from 2382; and plasma from 3771 donors. The KTB has also established 28 epithelial and 33 stromal cell lines from the cores; 4 of the epithelial cell lines have been immortalized using hTERT. Donors range in age from 18–86 years of age. 9% of donors to the KTB describe themselves as Hispanic/Latino. 5.2% of donors are Black or African-American. Using the Gail Risk Model, there is a bimodal distribution of life-time breast cancer risk among the donors: the largest peak is at 10% and a smaller one at 18%.

Conclusions: The KTB is a unique and invaluable research resource which is now open for business and accessible to researchers across the globe. We encourage researchers to avail themselves of this unique tissue resource and to also acquaint themselves with other sources of healthy breast tissue, i.e., the Love/Avon Army of Women [http://www.armyofwomen.org/].

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-21-02.
P5-23-02: Clinicopathological Features of Young Patients Age <35 Years with Breast Cancer in Japan.
Authors: Kataoka A , Tokunaga E , Masuda N , Shien T , Ohno S , Kinoshita T , Shimizu C
Published: June 2012

Background: The aim of this study is to clarify clinicopathological features of breast cancer in young women.

Materials and methods: Clinicopathological characteristics were compared between young (<35) patients and non-young (≥35) patients among 109,617 records of JBCS database registered from 2004 to 2009, and overall survival (10-yr OS) were calculated among 146,690 records from 1975 to 2000 with 8.6 years of median follow up period. Results: Clinicopathological factors of 2,982 young patients (2.7%) were compared with 106,295 non-young patients. Young patients had more familial history of breast cancer, more subjective symptom, less bilateral tumor, lower BMI, larger tumor, more inflammatory breast cancer, more positive node, less ER-positive, more HER2−positive, more triple-negative tumor, and more advanced TNM-stage.

Comparison of clinicopathological factors between young and non-young patients with breast cancer

Young patients were received more neoadjuvant chemotherapy and breast conserving therapy (BCT), compared with non-young patients.

Comparison of treatments between young and non-young patients with breast cancer

Eighty-percent of patients were received adjuvant therapy, among them, treatment rate of chemotherapy, molecular targeted therapy and radiation therapy was significantly higher in young patients than non-young patients. There was significant difference in 10-yr OS between young and non-young patients with Stage I-IIIA disease (Stage I 80% vs. 90%, IIA 78% vs. 85%, IIB 67% vs. 78%, IIIA 42% vs. 64%), but not with Stage IIIB and IIIC. Advanced TNM stage, lymph node metastasis and ER-negative tumor were significantly poorer prognostic factors for young patients by univariate analysis. Approximately 9% of young patients were at pregnancy at the time of diagnosis had more advanced disease and worse prognosis.

Conclusions: We conclude that young patients with breast cancer have an advanced or an endocrine-unresponsive tumor and have unfavorable outcome. Advocacy for awareness of breast cancer to young women and development of new targeted therapy against advanced, HER2−positve and triple-negative tumor are important to improve the survival of young patients with breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-23-02.
PD06-04: Uptake and Economic Impact of First-Cycle Colony Stimulating Factor Use during the Adjuvant Treatment of Breast Cancer.
Authors: Hershman DL , Wilde ET , Wright JD , Buono DL , Kalinsky K , Malin J , Tsai WY , Neugut AI
Published: June 2012

Background: In 2002, pegfilgrastim was approved by the FDA and the benefits of dose-dense breast cancer(BC) chemotherapy were reported. A meta-analysis revealed these benefits were limited to hormone receptor negative tumors (20% risk reduction), where hormone receptor positive cancers had a minimal 2% risk reduction. We examined first-cycle growth factor use(FC-CSF) before and after 2002 and estimated US expenditures for dose-dense chemotherapy by hormone receptor status.

Methods: We identified subjects in SEER-Medicare>65 years oldwith stage I-III BC between 1998 and 2005who had≥1 chemotherapy claim within one year of diagnosis. We classified those with an average cycle length <21 days as having had dose-dense therapy. The associations of patient, tumor, and physician-related factors with receipt of any CSF and FC-CSF use were analyzed using GEE. Costs and event-free life-years saved were estimated for patients by HR status.

Results: Among the 11,143 patients identified, 5,356(48.1%) hada CSF claim during therapy and 2095(18.8%) had FC-CSF. CSF use increased from 25.4% to 70.9%, FC-CSF increased from 6.4% to 46.9% and pegfilgrastim increased from 5% to 85%. During this time receipt of the combination of an anthracycline and a taxane increased from 12% to 47%. In a multivariable analysis, any CSF use was associated with age, treatment by an oncologist, and chemotherapy type; and negatively associated with black/Hispanic race, rural residence and shorter chemotherapy duration. FC-CSF use was associated also with higher SES. For hormone receptor negative patients, the cost per event-free life year saved was $5,512, with annual costs of $19.5 million. For hormone receptor positive patients, however, there was no savings in life years (and therefore no relevant cost per event-free life year saved) with annual costs of $38.8 million for those over 65. The annual costs were estimated at $86.1 million for the hormone receptor positive patient population incorporating all ages.

Conclusions: Our study demonstrated a widespread increase in the use of CSF's and specifically first cycle pegfilgrastim in elderly women receiving adjuvant chemotherapy for breast cancer. This 4-fold increase came shortly after published reports of the benefits of dose-dense therapy. While this approach is very cost-effective in women with hormone receptor negative tumors, it has come at great financial cost in women with hormone receptor positive tumors who are less likely to have a meaningful benefit. In order to reduce the total costs of cancer-care, efforts should be made to ensure that these treatments are reserved for only those who benefit substantially from their use.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD06-04.
PD09-01: Target-Based Therapeutic Matching in Early-Phase Clinical Trials in Patients with Advanced Breast Cancer and PIK3CA Mutations.
Authors: Janku F , Moulder SL , Wheler JJ , Stepanek V , Falchook GS , Naing A , Hong DS , Fu S , Piha-Paul SA , Luthra R , Tsimberidou AM , Kurzrock R
Published: June 2012

Background: Therapeutic matching based on underlying molecular abnormalities showed promising results in early-phase clinical trials. PIK3CA mutations may predict response to therapies with PI3K/AKT/mTOR inhibitors.

Methods: Tumors from patients with breast cancer referred to the Clinical Center for Targeted Therapy (Phase I Program) were analyzed for PIK3CA mutations. Patients with PIK3CA mutations were treated, whenever feasible, with agents targeting the PI3K/AKT/mTOR pathway.

Results: Of 54 patients analyzed, 15 (28%) had PIK3CA mutations. PIK3CA mutations were found in 5/9 (56%) metaplastic, 3/8 (38%) HER2−positive, 7/29 (24%) hormone receptor-positive, and 0/8 (0%) triple negative (excluding metaplastic) breast cancers (P=0.07). Of the 15 patients with PIK3CA mutations, 12 (80%) were treated in clinical trials containing a PI3K/AKT/mTOR pathway inhibitor (median age, 54; median number of prior therapies, 3). Of these 12 patients, 3 (25%, 95% CI 0.09−0.53) had stable disease for more than 6 months (SD≥6 months; n=1) or a partial response (PR; n=2). Breast cancer patients without PIK3CA mutations treated on the same protocols had a rate of SD≥6 months/PR of 8% (1/12; 95% CI 0.01−0.35, p=0.6). Of the 4 patients with a H1047R mutation treated with agents targeting the PI3K/AKT/mTOR pathway, 3 (75%) had SD≥6 months (n=1) or a PR (n=2) compared to 0 of 8 patients (0%) with other PIK3CA mutations (P=0.045). Patients with H1047R mutations had a median progression-free survival (PFS) of 8.5 months compared to 2 months in patients with other PIK3CA mutations (p=0.13).

Conclusion: Heavily pretreated patients with PIK3CA-mutant advanced breast cancer had a SD≥6 months/PR rate of 25% on protocols incorporating PI3K/AKT/mTOR. Patients with mutation H1047R had significantly longer SD≥6 months/PR rate compared to those with other PIK3CA mutations. Our observations suggest that screening for PIK3CA mutations is warranted in larger numbers of patients with advanced breast cancer when treatment with PI3K/AKT/mTOR pathway inhibitors is planned.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD09-01.
Abstract A30: Evaluating Spanish audiovisual materials about cancer clinical trials: Improving awareness among Hispanic patients and families
Authors: Quinn Gwendolyn , Wells Kristen , Antonia Teresita , Antolino Prado , Lopez Natalia , Gonzalez Luis , Alsina Melissa
Published: June 2012

Introduction: Hispanic cancer patients are underrepresented in cancer clinical trials (CCTs). Recent research suggests lack of knowledge and low health literacy among non-English speaking Hispanics may contribute to low accrual rates. Audiovisual materials offer advantages to Hispanic populations in that they have been shown to have: high acceptability; easy dissemination; and can also be viewed with family. Hispanic cancer patients/survivors and caregivers participated in focus groups to aid in developing a Spanish language DVD and booklet intervention. This multi-media intervention was designed to meet the specific needs of cancer patients who prefer speaking Spanish by increasing knowledge and decreasing uncertainty about CCTs. This pilot project explored the feasibility, and effectiveness of the multimedia intervention developed by our team.

Methods: 25 patients were randomized to either: (1) an intervention condition in which they were asked to view the DVD and read the accompanying brochure (n=13); or (2) a control condition in which they were asked to read the National Cancer Institute's brochure entitled “Si tiene cáncer…Lo que debería saber sobre estudios clínicos” (If You Have Cancer…What You Should Know About Clinical Trials; n=12). Self-report data on knowledge, attitudes toward participation in CCT, self efficacy for participating in CCT, likelihood of participating in a CCT, and receptivity to CCT information, were collected at two time points: 1) in person, following study enrollment, but before receipt of the intervention assignment; and 2) by telephone interview between 7 and 28 days following study enrollment.

Results: Twenty-five of twenty eight eligible patients (89%) participated in the study, mean age: 51.5 years; 48% female; 72% currently married). Despite the small sample size, trends in the data suggest participants provided with the multimedia DVD and brochure intervention believed themselves to be more capable of participating in a CCT, more receptive to learning about a CCT, and reported greater likelihood of participating in a CCT compared to patients provided standard NCI educational materials. Patients in both conditions were more knowledgeable about CCTs at follow-up.

Preliminary pilot data should be confirmed in a larger randomized control trial. However, a multi-media intervention found to be effective in increasing Hispanic patients’ confidence in participating and intention to participate in a CCT has the potential to be widely disseminated. Dissemination of such an intervention may improve the quality of care for Hispanic cancer patients who are eligible for CCTs.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):A30.
Abstract A122: The tyrosine kinase inhibitor MP470 inhibits RAD51-mediated homologous recombination and increases tumor cell radio- and chemosensitivity
Authors: Bristow Robert G. , Zhao Helen , Fraser Michael
Published: June 2012

MP470 is a tyrosine multi-kinase inhibitor whose targets include PDGFR, c-Kit and c-Met and is being tested as a single agent in Phase I clinical trials. In pre-clinical drug testing in vitro, we noted a reduction in the expression of RAD51, a key protein involved in the homologous recombination (HR) pathway of DNA double strand break (DSB) repair. We therefore tested whether MP470 can actually decrease HR function and thereby act as a radio- and chemosensitizer through a novel mechanism of action. We conducted qRT-PCR, Western blots, flow cytometric, inter-chromosomal DNA-dsb rejoining assays, subnuclear DSB recruitment and clonogenic survival using H1299 lung carcinoma cells with and without MP470 treatment. These cells incorporate a DR-GFP system which directly assesses HR by quantitative flow cytometry. As a single agent, MP470 treatments of 0.1 to 25 uM (24h) reduced RAD51 protein expression in H1299 cells in a dose-dependent manner. The ICD50 based on clonogenic assays was 0.66 uM; 1–2.5uM treatments reduced RAD51 levels by 50–60% with little effect on cell cycle distribution. This rules out that reduced RAD51 expression was secondary to cell cycle redistribution and decreased S phase following MP470 treatment. The same treatments reduced functional HR by 50% based on the DR-GFP assay. Using whole cell treatments with ionizing radiation (IR; 6Gy) and Mitomycin C (MMC) or UV microbeam sub-nuclear irradiation, we observed decreased expression and formation of RAD51 complexes at sites of DNA damage in MP470-treated (2.5uM) cells. Consistent with this finding, treatment of H1299 cells with 1 or 2.5uM MP470 led to significantly increased cell killing to IR and MMC (a drug that preferentially kill HR-defective cells) based on clonogenic assay. Confirmatory studies are ongoing with other cancer cell lines. We conclude that MP470 may have an additional mode of action by interfering with HR in cancer cells. Given that many cancers acquire radio- and chemoresistance and over-express RAD51, MP470 may be a novel drug to overcome RAD51-mediated therapeutic resistance. MP470 warrants further testing alone, or in combination with radiotherapy and chemotherapy, in pre-clinical and clinical efficacy studies with the development of HR-associated biomarkers. (Supported by funds from SuperGen, a Terry Fox Hypoxia Project Program Grant and a CCS Reseach Scientist award to RGB.).

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A122.
Abstract A127: Combination therapy targeting EGFR/MET crosstalk using nanotechnology improves photodynamic therapy treatment of pancreatic cancer
Authors: Zheng Lei Z. , Rai Prakash , Spring Bryan , Mai Zhiming , Evans Conor , Hasan Tayyaba
Published: June 2012

Pancreatic cancer (PanCa) is very difficult to treat due to its inherent resistance to most therapies. First line chemotherapy only has a 5% response rate, yielding a median survival of 6 months and a 5-year survival rate of < 5%. Combinations of chemotherapy with numerous targeted therapies only showed modest benefits. In a pilot clinical trial, Photodynamic Therapy (PDT) showed considerable promise as an emerging alternative treatment modality for PanCa in humans by improving median survival from 6 to 9 months, which led to our subsequent investigation of a rationally designed molecularly targeted combination therapy to enhance PDT treatment of PanCa in an orthotopic murine model.

Targeted biological therapies in PanCa include an EGF Receptor (EGFR) antibody, C225 which has shown no survival benefits in humans either alone or in combination with other modalities. One of the mechanisms involved in the development of resistance to EGFR targeted therapy is the crosstalk between EGFR and MET signaling pathways. MET is also a growth factor receptor that is frequently deregulated in pancreatic cancer. In some cancers, the EGFR and MET signaling pathways synergistically drive proliferative and metastatic growth. To achieve effective tumor control it is vital that both EGFR and MET pathways are targeted simultaneously. In this preclinical study, we have developed an innovative nanoscale multidrug delivery system that targets the EGFR/MET crosstalk in combination with PDT. To target EGFR we are using C225 antibody while the MET activation is suppressed using a small molecule inhibitor PHA-665752.

Major findings of this work include: 1) Our nanoscale multidrug delivery system enabled higher payloads of the PDT agent and PHA-665752 to be delivered with reduced systemic toxicity. In our nano-construct, the C225 is now delivered intracellularly into cancer cells thus allowing the targeting of both intracellular and membrane EGFR, as opposed to carrier-free C225 delivery which only down-regulates the cell surface EGFR level. 2) Intracellular targeting of EGFR by encapsulated C225 sensitized the cancer cells to PDT treatment. This combination showed greater efficacy in reducing the EGFR levels and improved PDT treatment effect by showing a greater reduction of the local tumor burden, compared to using carrier-free C225 extracellularly. 3) Blocking the EGFR/MET crosstalk with both C225 and PHA-665752 further enhanced PDT treatment by reducing the local tumor burden. We are further investigating if this combination treatment regimen reduces tumor metastasis to distal organs and the optimal scheduling of individual biological treatments.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A127.
Abstract A129: Targeted delivery of therapeutics to tumor cells and the tumor microenvironment
Authors: Moura Vera , Lacerda Manuela , Figueiredo Paulo , Corvo Maria Luisa , Cruz Maria Eugénia , Pedroso de Lima Maria C. , Simões Sérgio , Moreira João Nuno
Published: June 2012

Human cancer is a complex disease caused by genetic instability and accumulation of multiple molecular alterations. Tumor growth and metastasis depend on the development of a neovasculature by a process called angiogenesis, which is controlled by numerous pro- and antiangiogenic factors. Therefore, vascular targeting emerges as an attractive therapeutic approach, since angiogenic blood vessels express distinctive molecular markers with direct access by the therapeutic agent. Moreover, ablation of immature angiogenic vessels causes reduction of the interstitial pressure gradient in the tumor periphery, improving drug delivery through the highly permeabilized vessel wall. Hence, additional therapeutic gains will be expected by “starving” tumor cells to death and by increasing the concentration of the therapeutic agent in the target cell.

The present work, is aimed at investigating the ability of a system consisting of a ligand coupled to the extremity of poly(ethylene glycol)-grafted liposomes, containing doxorubicin (DXR), to simultaneously target human tumor cells and endothelial cells of tumor blood vessels. Cellular association studies were conducted by flow cytometry, fluorimetry and confocal microscopy with rhodamine-labeled liposomes. Competitive inhibition and mechanistic assays were also performed by fluorimetry. Cytotoxicity was evaluated with the MTT assay and biodistribution performed on Balb/c nude female mice bearing orthotopic implanted tumors was analyzed by radioactivity counts of a lipid and a drug tracer ([3H]CHE and [14C]DXR, respectively).

Our results show a substantial increase in the levels of association for ligand-targeted liposomes, in vitro as well as ex vivo, in tumor cells removed from patients, after mastectomy or tumorectomy. These results suggest that internalization occurs, most likely through the clathrin-mediated endocytic pathway. Cytotoxicity studies show that ligand-targeted liposomes are more cytotoxic than the control formulation (4 to 180-fold), against tumor and endothelial cells, indicating that binding and internalization of the system are contributing to a more efficient delivery of the payload to the target cells. In vivo experiments report a higher tumor accumulation of the radiolabeled targeted system over non-targeted liposomes (approximately 18-fold). The observed improved tumor targeting is likely due to a strong vascular targeting component that is taking place in vivo. The data generated so far indicate that the same technological platform is able to target two distinct cell populations within the tumor niche. Overall, these results represent a novel and a valuable contribution for delivery strategies to the tumor and its microenvironment.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A129.
Abstract A130: Effects of a novel liposomal formulation of fenretinide on human neuroblastoma cell growth, apoptosis and angiogenesis
Authors: Di Paolo Daniela , Caffa Irene , Pastorino Fabio , Loi Monica , Marimpietri Danilo , Brignole Chiara , Perri Patrizia , Cilli Michele , Nico Beatrice , Ribatti Domenico , Ponzoni Mirco , Pagnan Gabriella
Published: June 2012

Neuroblastoma (NB) is an embryonal tumor originating from the simpatico-adrenal lineage of the neural crest and developing virtually at any site of the sympathetic nervous system. It approximately accounts for about 15% of all paediatric oncology deaths. NB is characterized by different clinical presentations and courses. Metastatic tumors at diagnosis remains a clinical challenge, despite advances in multimodal therapy. Retinoids are a class of compounds known to induce both terminal differentiation and apoptosis/necrosis of NB cells. Among them, fenretinide (HPR), thanks to its good safety profile in humans, has been considered one of the most promising synthetic retinoids tested as chemopreventive agent but it is only partially efficacious due to both a scanty oral delivery and a rapid methabolism. Here, we have developed a novel liposomal HPR by which the drug was encapsulated into sterically stabilized liposomes [SL-(HPR)] according to the reverse-phase evaporation method. This procedure led to a higher drug encapsulation and to better size and stability in organic fluids when compared to our previously HPR-entrapped liposome preparation (Pagnan et al., Int.J.Cancer 1999;81:268). Moreover, liposomes were coupled with NGR peptides that target the tumor endothelial cell marker, the aminopeptidase N [NGR-SL-(HPR)] (Pastorino et al, Cancer Res 2006;66:10073). The in vivo sensitivity of NB to the HPR liposomal preparations was tested against an established orthotopic NB xenograft animal model. Tumor-bearing mice treated with NGR-SL-(HPR) lived statistically longer than mice un-treated or treated with free HPR [NGR-SL-(HPR) vs both control and HPR: P<0.0001]. SL-(HPR) resulted in a statistically improved survival [SL-(HPR) vs both control and HPR: P<0.0001] but with a less extent if compared with that obtained with NGR-SL-(HPR) [SL-(HPR) vs NGR-SL-(HPR): P=0.01]. Double staining of primary tumor sections with TUNEL and with antibodies against the NB specific antigen, NB84a, and against either factor VIII or smooth muscle antigens evidenced that HPR reduced NB growth through both antitumor and angiostatic effects, mainly when delivered by NGR-SL-(HPR). These results were confirmed by a marked reduction of intratumoral vessel counts together with a down-modulation of both matrix metalloproteinases MMP2 and MMP9.

The use of this novel targeted delivery system for the apoptotic and anti-angiogenic drug, fenretinide, could be considered as an adjuvant tool in the future treatment of NB patients.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A130.
Abstract A132: Development of efficient macromolecular prodrugs derived from dendritic polyglycerol
Authors: Calderon Marcelo , Welker Pia , Licha Kai , Graeser Ralph , Kratz Felix , Haag Rainer
Published: June 2012

Introduction: Utilizing the Enhanced Permeation Retention Effect (EPR) for passive targeting is one of the novel approaches for tumor-selective drug delivery. Polymer-based nanocarriers, especially those of dendritic architecture, have gained increasing interest for encapsulating or coupling diagnostic or therapeutic agents. Chemical conjugation to a dendritic scaffold, thereby exploiting the high multivalency, allows for the covalent attachment of different kinds of bioactive molecules (imaging agents, drugs, targeting moieties, or biocompatible molecules) in a controlled ratio. (1) Hyperbranched polyglycerol is a potent alternative to perfect dendrimers for biomedical applications because of its ease of preparation, non-immunogenicity, tuneable molecular weight, high water-solubility and structural flexibility through end group modification. (2)

Here we present a comprehensive study for the development of macromolecular doxorubicin-polyglycerol prodrugs. The effects of the conjugation approach, the polymeric architecture, the cleavable linker and the drug loading over the final properties are analyzed.

Results and Discussion: Hyperbranched polyglycerols partially modified with azido, propargyl, amine or polyethylene glycol were prepared with overall yields higher than 60%. Different reactions, e.g click coupling and Michael addition, were evaluated for the conjugation of several doxorubicin derivates to the polyglycerol scaffolds. UV-Visible, 1H-NMR, GPC and HPLC were used to demonstrate the obtention of macromolecular prodrugs with several molecular weights, architectures and different cleavable linkers. The conjugates showed rapid and selective release of doxorubicin after being triggered by a change in pH or in presence of enzymes, accordingly to the nature of conjugated prodrugs.

The antiproliferative activity assessed against two human tumor cell lines AsPC1 LN (pancreatic carcinoma) and MDA-MB-231 LN (mamma carcinoma) showed less (2- to 10-fold) cytotoxicity than the corresponding free drugs. Cellular uptake was confirmed by fluorescence microscopy. In all cases, the conjugates showed to be active in the low micromolar range that is relevant for further preclinical studies of anticancer prodrugs.

The in vivo efficacy was tested in ovarian carcinoma A2780 xenograft model. With respect to antitumor efficacy, some of the conjugates manifested excellent antitumor effects with complete tumor remissions up to day 30. No significant changes in body weight were observed even after administration of 3-fold the maximal tolerated dose for free doxorubicin.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A132.
Abstract A161: Acquired resistance to combination treatment with TMZ and ABT-888 is mediated by both BER and HR DNA repair pathways
Authors: Liu Xuesong , Han Edward K. , Anderson Mark G. , Shi Yan , Semizarov Dimitri , Wang Gang , McGonigal Thomas , Roberts Lisa , Iasko Ioren , Palma Joann , Zhu Gui-Dong , Penning Thomas , Rosenberg Saul , Giranda Vincent , Luo Yan , Leverson Joel , Johnson Eric F. , Shoemaker Alexander R.
Published: June 2012

Many established cancer therapies involve DNA-damaging chemotherapy or radiotherapy. Gain of DNA repair capacity of the tumor represents a common mechanism employed by cancer cells to survive DNA-damaging therapy. Poly (ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme that is activated by DNA-damage and plays a critical role in base excision repair (BER). Inhibition of PARP represents an attractive approach for the treatment of cancer. Previously, we have described the discovery and characterization of a potent PARP inhibitor, ABT-888. ABT-888 potentiates the activity of DNA-damaging agents such as temozolomide (TMZ) in a variety of preclinical models. Previously, we demonstrated that ABT-888 potentiated the cytotoxic effect of TMZ by converting TMZ-induced single strand DNA breaks (SSB) to double strand breaks (DSB). We report here the generation of HCT116 cells resistant to treatment with TMZ and ABT-888 (HCT116R cells). HCT116R cells exhibit decreased H2AX phosphorylation in response to the treatment with TMZ and ABT-888 relative to parental HCT116 cells. Microarray and western blot studies indicate that HCT116R cells have decreased PARP-1 and elevated Rad51 expression levels. HCT116R cells are dependent on Rad51 for proliferation and survival, as demonstrated by inhibition of proliferation and induction of apoptosis upon treatment with Rad51 siRNA. In addition, HCT116R cells are more resistant to radiation than the parental HCT116 cells. Our study suggests that cancer cells up-regulate the homologous recombination DNA repair pathway to compensate for the loss of BER, which may account for the observed resistance to the treatment with TMZ and ABT-888.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A161.
Abstract A168: Quantitative high-throughput screening for inhibitors of human apurinic/apyrimidinic endonuclease APE1
Authors: Dorjsuren Dorjbal , Jadhav Ajit , Kulkarni Avanti , McNeill Daniel , Austin Christopher P. , Wilson David M. , Shen Min , Simeonov Anton
Published: June 2012

The major human apurinic/apyrimidinic endonuclease APE1 plays a pivotal role in the repair of spontaneous hydrolytic, oxidative, and non-enzymatic alkylation base damage via the DNA base excision repair (BER) pathway. The increased activity of APE1, often observed in tumor cells, is thought to contribute to the development of resistance to various anticancer drugs; conversely, its down-regulation sensitizes tumor cells to DNA damaging agents via induction of apoptosis. Therefore, inhibiting APE1 within the BER pathway in cancer cells is an attractive strategy in the attempts to overcome chemotherapeutic resistance. Despite ongoing efforts, potent specific inhibitors of APE1 have yet to be discovered.

We developed a fluorogenic substrate operating in the red-shifted fluorescence spectral region to configure a highly robust kinetic assay for use in 1536-well based automated high-throughput screening (HTS). The assay was used in a titration-based screen of the LOPAC1280 library to identify potential APE1 inhibitors which were further validated and profiled in a panel of assays including radiotracer-based incision assay, Thiazole Orange fluorophore displacement test for promiscuous DNA binders, and E. coli Endo IV counterscreen. Select compounds which passed the above validation steps were progressed to studies of increased biochemical complexity and were shown to inhibit abasic-site incision activity in whole cell protein extracts and to potentiate the genotoxic effect of methyl methanesulfonate (MMS), consistent with suppression of BER on a cellular level. Subsequently, a fully automated HTS was conducted against a collection of 241,291 diverse compounds tested as 7-concentration series at a 4 uL reaction volume in 1536-well plate format. To our knowledge, this represents the first large-scale HTS to identify inhibitors of APE1, and provides a key first step in the development of novel agents targeting BER for cancer treatment.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A168.