bluuebunny/crossref_metadata_2025 huggingface dataset:
Associations between estrogen receptor (ER) Alpha expression levels and ER genotypes.
Authors: Henry NL , Shak S , Banerjee M , Skaar T , Palmer G , Braman M , Stearns V , Flockhart DA , Kleer C , Hayes DF , Rae J
Published: December 2010

Abstract #3049

Background: Estrogen receptors (ER) and associated factors, including progesterone receptors (PgR), modulate estrogenic effects both in normal tissue and in hormone receptor (HR)-positive breast cancers. ERα expression occurs in the majority of breast cancers, although the level of overexpression varies between tumors. Multiple single nucleotide polymorphisms (SNPs) in the genes that encode ER, termed ESR1 (ERα) and ESR2 (ERβ), have been shown to affect phenotypic outcomes, including breast cancer risk, bone mineral density, hot flashes, and lipid levels. We hypothesized that SNPs in genes that encode ER may affect level of ER overexpression.  Methods: DNA was extracted from white blood cells from 100 subjects with HR-positive breast cancer enrolled in a tamoxifen observational study. SNPs in ESR1 (XbaI: rs#9340799, PvuII: rs#2234693) and ESR2 (01: rs#1256049; 02: rs#4986938) were determined from germline DNA using TaqMan. ER overexpression in paraffin-embedded formalin-fixed tumor specimens was quantified with immunohistochemistry (IHC) of tumor specimens on slides (Ventana Image Analysis System) and with RT-PCR using the Oncotype DX breast cancer assay (Genomic Health, Inc). Gene expression of other ER-associated genes (PgR, BCL2, and SCUBE2) was determined using RT-PCR (Oncotype DX). Expression of ER and associated genes across ER genotype was performed using the Kruskal-Wallis test. For all analyses, a p value of <0.05 was considered statistically significant.  Results: ER expression assessed using IHC and RT-PCR was statistically significantly correlated, with a Pearson correlation coefficient of 0.43 (p=0.0006). However, there was no association between the ESR1 or ESR2 genotypes and ER expression assessed by either method. A trend between ESR1 XbaI genotype and PgR expression by RT-PCR was noted (p=0.08 for gene-dose effect). No other associations between ER polymorphisms and expression of ER-related genes were identified.  Conclusions: SNPs in genes encoding for ER do not appear to be associated with level of ER expression in breast cancer. Differences in ER expression between individual tumors are likely due to mechanisms other than these inherited mutations in the ER genes.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3049.
Estradiol downregulates miR-21 expression and miR-21 gene targets in MCF-7 breast cancer cells.
Authors: Wickramasinghe NS , Manavalan TT , Riggs KA , Li Y , Klinge CM
Published: December 2010

Abstract #3051

Select changes in microRNA (miRNA) expression correlate with diagnostic markers used in breast cancer therapies, e.g., estrogen receptor α (ERα) and tumor grade. However, no one has examined how estradiol (E2) regulates miRNA expression in breast cancer cells. Here miRNA microarrays were used to identify miRNA genes regulated by E2 in MCF-7 breast cancer cells. Twenty-five miRNAs were E2-regulated and select results were confirmed by quantitative-PCR. E2 reduced the expression of miR-21, an oncogene, and repression was inhibited by the antiestrogen ICI 182,780, ERα knockdown by siRNA, and by pre-treatment with Actinomycin D or cycloheximide. Thus, E2-ERα reduces miR-21 expression by primary transcriptional and secondary target activities. The effect of E2 on luciferase reporters containing the miRNA recognition elements (MREs) from the 3'-UTRs of 8 putative miR-21 regulated genes: CCM1, SKI, TGFB1, PDCD4, RAB6A, RAB6C, RASA1, and RASGRP1 was tested in MCF-7 cells. E2 increased luciferase with the MREs from TGFB1, PDCD4, RASA1, and RASGRP1, and from the full length 3' UTR of the PDCD4 gene, consistent with an E2-mediated decrease in miR-21 resulting in increased stability of Renilla mRNA and increased luciferase activity. Antisense to miR-21 increased luciferase from the TGFB1,PDCD4, RAB6A, and RASGRP1 reporters, consistent with these MREs being bona fide miR-21 targets. The E2-mediated decrease in miR-21 correlated with increased expression of miR-21-targets PDCD4, PTEN, and Bcl-2 at the protein level and these increases were blocked by AS to miR-21 and by siRNA knockdown of ERα. These results identify miR-21 as an ERα- regulated miRNA in MCF-7 cells.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3051.
Ixabepilone plus capecitabine vs capecitabine in patients with triple negative tumors: a pooled analysis of patients from two large phase III clinical studies.
Authors: Rugo HS , Roche H , Thomas E , Blackwell K , Chung H , Lerzo G , Volles LA , Poulart V , Perez E
Published: December 2010

Abstract #3057

Introduction: Patients (pts) with ER/PR/HER2 negative advanced breast cancer (triple negative, TN, basal-like) have limited treatment options and a poor prognosis. Ixabepilone (ixa), the first in a new class of antineoplastic agents, showed clinical benefit in combination with capecitabine (C) in 2 large clinical trials in metastatic breast cancer (MBC) pts either resistant to (study 046; JCO, 2007) or pretreated with anthracycline (A) and taxanes (T) (study 048). In 048, ixa + C, compared to C alone, demonstrated significant increases in PFS (HR 0.79 [0.69-0.90]) and ORR (43 vs. 29%). A trend towards increased OS was seen in both 048 (HR 0.90 [0.78-1.03]) and 046 (HR 0.90 [0.77-1.05]), which did not reach statistical significance. Here we present a pooled analysis of efficacy endpoints (ORR, PFS and OS) in pts with TN disease from these 2 phase III studies.  Methods: 1973 pts with MBC previously treated with A and T were randomized in 2 phase III trials (046 and 048) to receive either ixa (40 mg/m2 IV over 3h Q3w) + C (1000 mg/m2 PO BID x14d Q3w) or C alone (1250 mg/m2 PO BID x14d Q3w). Due to the similarity of the study populations, individual pt data from both studies was pooled to better evaluate treatment effect within pre-planned patient subgroups.  Results: 443 pts had TN disease in the two studies combined. ORR and PFS were superior in pts receiving combination therapy compared to those on C alone with a trend towards improved survival that did not reach statistical significance.    Conclusions: Ixa + C is the first combination to show statistically significant PFS benefit in pts with advanced TN breast cancer from a pooled analysis of 2 phase III trials. Clinical benefit was consistently seen pts with TN disease in the individual studies as well.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3057.
Activity and mechanism of action of histone deacetylase inhibitors in trastuzumab resistant breast cancer.
Authors: Radke S , Kumar A , Jones L , Tuck DP , Harris LN
Published: December 2010

Abstract #3060

Introduction: The Her2 antibody trastuzumab (T) is the first biological therapy that has proven the value of Her2 blockade in breast cancer. However, not all patients respond to trastuzumab and relapses occur after this treatment. Several studies suggest that histone deacetylase inhibitors (HDACis) are active in Her2-amplified breast cancer but none of them have addressed the role of HDACis in trastuzumab-resistant breast cancer. HDACis act by inhibiting the deacetylation of histones and other non-histone proteins such as Hsp90. Our goal is to study the activity, optimal sequencing and mechanism of action of HDACis in Her2-amplified cell lines, which demonstrate either de novo or acquired resistance to trastuzumab.  Methods: T-sensitive and Her2-overexpressing BT474 & SkBr3, T-resistant BT474 and de novo T-resistant cell lines MDA-MB361, MDA-MB453, UACC812 and UACC893 were used for all experiments. The HDACi TSA (0-1uM) and trastuzumab at 100ug/mL were used for proliferation assays applying WST1 reagent (Roche). Western-immunoblotting was performed using cell lysates from untreated and treated cells. Proteolytic cleavage of caspase-3 and PARP was analyzed as indicator for apoptosis, Akt expression and phosphorylation for survival, Her2 and Erk1/2 expression and phosphorylation for proliferation and Hsp90 and Hsp70 were analyzed as key enzymes for chaperone activity.  Results: TSA inhibited proliferation in all cell lines [IC50 100-300 nM]. The addition of trastuzumab was antagonistic in de novo T-resistant cell lines MDA MB 453, UACC 812 and 893 but did not change the effect induced by TSA in acquired T-resistant cells (BT474_H100). Her2 expression decreased in TSA and TSA+T treated cells but not in cells treated with trastuzumab alone. Erk1/2 phosphorylation decreased in TSA and TSA+T treated cells but was not affected by trastuzumab alone. Similar phosphorylation patterns were observed regarding Akt. Of note, Akt, Erk1/2, Hsp90 and Hsp70 levels did not change. Finally, TSA induced caspase-3 and PARP cleavage when given as single agent or in combination with trastuzumab.  Discussion: This study suggests that HDACis are active in both trastuzumab-sensitive and de novo or acquired trastuzumab-resistant cell lines. However, use of trastuzumab together with TSA may be antagonistic in tumors that are resistant against trastuzumab. Further studies are required in these cell lines in order to elucidate the mechanism of resistance against trastuzumab and the mechanism of the here observed antagonistic effect between trastuzumab and TSA.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3060.
Synthetic lethality when combining phosphoinositide 3-kinase alpha and beta catalytic subunit-directed RNAi and estrogen deprivation for estrogen receptor positive breast cancer: implications for clinical trial design with pharmacological inhibitors.
Authors: Crowder RJ , Phommaly C , Hoog J , Tao Y , Saporita A , Weber JD , Huntsman DG , Ellis MJ
Published: December 2010

Abstract #3063

Background: Endocrine therapy with estrogen deprivation (ED) induces cell cycle arrest in sensitive estrogen receptor positive (ER+) breast cancers, but typically not apoptosis, thus relapse is common despite ED due to residual surviving tumor cells. The phosphoinositide 3-kinase (PI3K) pathway, which promotes cell survival, is hyperactivated in ER+ breast cancer due to mutations of genes in the PI3K signaling cascade, most commonly PIK3CA. We therefore investigated the role of p110α and p110β, the gene products of PIK3CA and PIK3CB, in promoting cell survival in ER+ breast cancer.  Materials and Methods: RNA interference (RNAi) was used to selectively inhibit p110α and p110β expression in the ER+, PIK3CA mutant MCF-7 and T47D cell lines; the ER+, PIK3CA wild-type but PIK3CB gene amplified HCC712 cell line; and the ER-, PIK3CA and PIK3CB wild-type MDA-MB-231 cell line. Western blotting was used to confirm p110α and p110β knockdown efficiencies and to determine the effects of specific knockdowns on PI3K pathway signaling. Cell line growth was measured using a resazurin reduction assay. Apoptosis was quantified using TUNEL/Hoechst staining. Gene copy number for PIK3CB was assessed by FISH in cell lines and tumor samples.  Results: PIK3CA RNAi inhibited growth and activated apoptosis in all tested ER+ cell lines under ED, whereas the addition of estrogen reversed PIK3CA RNAi-induced apoptosis. PIK3CB RNAi inhibited proliferation and promoted apoptosis in the absence of estrogen only in the PIK3CB-gene amplified HCC712 cell line. In combination, PIK3CA and PIK3CB gene knockdowns produced a synergistic apoptotic effect on T47D and HCC712 cell lines, but not in MCF-7 cells which contain low levels of p110β protein. In contrast PIK3CA and PIK3CB RNAi did not promote apoptosis in the ER- MDA-MB-231 cell line. Finally, since PIK3CB gene amplification has not been described previously we conducted a screen by FISH and array CGH and detected low-level PIK3CB copy number gain or amplification in ∼5% of clinical samples from a series of breast cancer patients representing diverse clinical phenotypes (ER+, ER-, ERBB2+).  Conclusions: Inhibition of the PI3K pathway through suppression of PI3K catalytic subunit expression produces a synthetic lethal effect in the absence of estrogen specifically in ER+ breast cancer cells. These data establish a preclinical rationale for combining endocrine therapy with PI3K pharmacological inhibitors in ER+ breast cancer, but suggest that both PIK3CA and PIK3CB are therapeutic targets and gene mutation or amplification in both catalytic subunits may have to be taken into account when identiying a sensitive population for PI3 kinase-directed therapy.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3063.
Inhibition of 6-phosphofructo-2-kinase suppresses breast tumor growth in vivo.
Authors: Clem B , Telang S , Clem A , Goswami U , Chesney J
Published: December 2010

Abstract #3064

Phosphofructo-1-kinase, a rate-limiting enzyme of glycolysis, is activated in neoplastic cells by fructose-2,6-bisphosphate (Fru-2,6-BP), a product of four 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase isozymes (PFKFB1-4). The inducible PFKFB3 isozyme is constitutively expressed by neoplastic cells and required for the high glycolytic rate and anchorage-independent growth of ras-transformed cells. We report that siRNA silencing or small molecule inhibition (3PO) of PFKFB3 causes a decrease in cell proliferation and metabolic flux in several breast cancer cell lines (MDA-MB-231, MDA-MB-468, BT-549, BT-474, SK-BR-3, ZR-75-1, MCF-7, and MCF-10A). Furthermore, 0.075mg/g 3PO administered via intraperitoneal injection suppresses tumor growth in two transgenic mouse models of breast cancer (MMTV-H-ras: 30% inhibition; MMTV-Erbb2(Her2/neu): 60% inhibition). Interestingly, the Her2 positive cell lines (SK-BR-3, BT-549) and the Her2 mouse transgenic model were more susceptible to PFKFB3 inhibition suggesting that the Her2 phenotype may be more sensitive to disruption of glycolytic flux. Taken together, these data support the clinical development of 3PO and other PFKFB3 inhibitors as chemotherapeutic agents against breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3064.
Adiponectin activates tumor suppressor LKB1 and AMP-activated protein kinase signaling to inhibit malignant properties of breast cancer cells.
Authors: Smith LT , Knight BB , Saxena NK , Sharma D
Published: December 2010

Abstract #3067

Introduction: The prevalence of obesity in the developed world has reached epidemic proportions in recent years. Obese breast cancer patients exhibit a higher risk for metastasis, larger tumor burden and poorer response to endocrine therapy. Therefore, it is very important to understand the adverse effects of obesity on breast cancer in order to devise appropriate new approaches to their treatment. Obesity is considered an endocrine disorder and serum levels of adiponectin, an adipocytokine proposed to have therapeutic potential, get significantly lowered with obesity. More recently, low serum adiponectin levels were associated with increased risk and more aggressive phenotype (larger tumor size and high histological grade) of breast cancer in women. Recently, anti-proliferative and pro-apoptotic response of adiponectin was shown in breast cancer cells but the molecular mechanisms governing the anti-cancer effects of adiponectin largely remain unknown. In the present study, we found a novel mechanism underlying adiponectin action involving upregulation of tumor suppressor LKB1 and activation of AMPK (AMP-activated protein kinase) signaling to inhibit malignant properties of breast cancer cells.  Methods and Results: Adiponectin inhibited malignant properties such as invasion and migration of breast cancer cells in matrigel invasion, scratch migration and quantitative Electric Cell-Substrate Impedance Sensing (ECIS) invasion and migration assays. Interestingly, adiponectin induced phosphorylation of AMPK at Thr 172 in breast cancer cells. Adiponectin treatment also affected downstream targets of mTOR signaling pathway, including decreased phosphorylation of p70S6K showing the involvement of mTOR-S6K axis. Intriguingly, we found that adiponectin increased the expression of tumor suppressor LKB1 in breast cancer cells. Co-immunoprecipitation assays revealed that LKB1 co-immunoprecipitated with tumor suppressor TSC2. Increase in expression of upstream kinase LKB1 might directly regulate adiponectin induced activation of AMPK. We also found that breast cancer cells transfected with wild-type LKB1 plasmids increased phosphorylation of AMPK and decreased phosphorylation of p70S6K showing decrease in mTOR activity. In contrast, breast cancer cells transfected with kinase dead LKB1 decreased phosphorylation of AMPK and increased activation of p70S6K.  Discussion: Taken together these data indicate a novel crosstalk between adiponectin and tumor suppressor LKB1 that modulates AMPK-S6K axis and inhibits metastatic properties, invasion and migration of breast cancer cells. The influence of adipocytokine, adiponectin on breast carcinogenesis is just beginning to be elucidated and our study is the first to show the direct involvement of tumor suppressor genes LKB1 and TSC2 in anti-cancer effects of adiponectin.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3067.
SATB1: a 'master genome organizer' in mammary carcinogenesis.
Authors: Worku D , Jiang WG , Mansel RE , Mokbel K
Published: December 2010

Abstract #3070

Background: SATB1 is a nuclear protein that has been recently reported to be a 'genome organizer' that delinates specific epigenetic modifications at target gene loci, directly up-regulating metastasis-associated genes while down-regulating tumor-suppressor genes. This study aimed to examine the level of mRNA expression of SATB1 gene in normal and malignant breast tissue and correlate the level to the clinico-pathological parameters.  Material and Methods: One hundred and fifteen breast cancer tissue and 31 normal breast tissues were analyzed. Levels of transcription of SATB1 were determined using real-time quantitative PCR and were analyzed against TNM stage, nodal involvement, tumor grade and clinical outcome.  Results: The levels of SATB1 mRNA were significantly higher in malignant compared with normal breast tissue (p=0.0167). The expression of SATB1 mRNA was demonstrated to increase with increasing TNM stage (TNM1 vs. TNM2, p=0.0264; TNM2 vs. TNM3, p=0.024) and increasing tumor grade (grade 1 vs. grade 3, p=0.017; grade 2 vs. grade 3, p=0.0437; grade 1 vs. grade 2&3, p=0.021). After a median follow up of 10 years, there was a trend for tumors with higher SATB1 expression levels to be associated with shorter overall survival times.  Discussion: These results are consistent with the notion that SATB1 acts as the 'master genome organizer' in tumorigenesis of human breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3070.
The RNA binding protein HuR/ELAV1 regulates the estrogen receptor and epidermal growth factor receptor beta expression in BT 474 cells.
Authors: Licata LA , Hostetter C , Keen JC
Published: December 2010

Abstract #3076

The RNA binding protein HuR has been shown to increase the mRNA stability of the majority of transcripts to which in binds. Recent data has linked the cytoplasmic distribution of HuR to the tumorigenesis process in many cancer types. HuR levels were found to be higher in more metastatic, higher grade breast tumors, suggesting that it may play a role for stabilization of growth-promoting transcripts in breast cancer cells. Previously, our lab has shown that the DNA methyltransferase inhibitor 5-aza- 2'deoxycytidine (AZA) and histone deacetylase inhibitor Trichostatin A (TSA) decreased the cytoplasmic accumulation of HuR in MDA-MB-231 and MCF-7 cells. Therefore, to examine the role of HuR in the more tumorigenic, estrogen receptor (ER) positive, Tamoxifen resistant BT 474 cells were treated with AZA/TSA or siRNA probes specifically targeting HuR expression. The BT 474 cells had a baseline increase in the cytoplasmic distribution of HuR as compared to MCF-7 and MDA-MB-231 cells. The half-life of ER mRNA was also increased. Following AZA/TSA treatment for 24-96 hours, cytoplasmic HuR was noticeably lower after 48 hours of treatment. Subsequent mRNA levels of both ER and epidermal growth factor beta (erbB2/HER2) were also found to drop with treatment. siRNA inhibition of HuR had a similar effect on the mRNA levels. Biotin pulldown assays using probes specific for the ER 3' UTR showed HuR binding was decreased with AZA/TSA treatment. These were similar findings as previously reported in MCF7 cells. Since ER and erbB2 are central to hormonal therapy, Tamoxifen sensitivity was assessed using BT 474 cells transfected with siRNA probes specifically targeting HuR expression. Cellular viability following Tamoxifen treatment was significantly decreased when HuR expression was inhibited and Tamoxifen sensitivity was restored. Similar studies investigating the role of HuR in herceptin resistance are currently ongoing. Taken together, our data suggests that HuR plays a key role in both de novo and acquired Tamoxifen resistance.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3076.
Cytotoxic effects of crystal proteins from Bacillus thuringiensis against breast cancer cells.
Authors: Tharakan BD , Devaki G , Nair HB , Padikkala J
Published: December 2010

Abstract #3077

Insecticidal crystal proteins (ICPs) produced by the Gram-positive bacterium, Bacillus thuringiensis during sporulation, are widely used as bioinsecticides against lepidopteran larvae. The pro-protein, upon ingestion by larvae, is processed to an active form by proteases in midgut and binds to a specific receptor on the membrane surface of epithelial gut cells. This leads to permeable pore formation in the membrane surface and finally the death of the insects. The genes for crystal protein appear to reside on plasmids and shows high degree of diversity. Recent studies have shown that these potent toxins also exhibit selective cytotoxic activity against human breast cancer cells. In the present study, the cytotoxic effect of proteins extracted from three native strains of Bacillus thuringiensis from the Western Ghats of Kerala (India) was investigated. Crysal protein was harvested from 72h old cultures in sporulating medium, after confirming lysis of cells and release of crystal protein. The proteins were isolated and characterized through various chromatographic and electrophoretic procedures. The pro-protein isolated was activated and subjected in vitro cytotoxicity assay on various normal as well as breast cancer cell lines including MCF-7,MDA-MB-231, ZR-75 and SKBR3. The protein was found to have strong cytocidal activities against tumour cells and treated cells showed remarkable morphological alterations including cytoplasmic blebbing, cytoskeletal alterations etc. Considering these results, we suggest that the receptor mediated action of crystal proteins against tumour cells may have a new target in the therapeutic as well as diagnostic field of cancer therapy.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3077.
Human papillomavirus in breast carcinomas of Korean women.
Authors: Choi J , Lee K , Kim W , Lee S , Lim H , Choi Y , Kim D , Lee J , Nam S , Yang J
Published: December 2010

Abstract #3086

Introduction  The association between human papillomavirus (HPV) and cervical cancer is well documented. However, it remains unclear whether there is also a correlation between HPV infection and human breast cancer. The aim of this study was to investigate the status of HPV-DNA in breast carcinoma of Korean women and to examine the possible association between HPV and breast cancer development.  Patients and Methods  We examined the HPV-DNA of 154 patients including 123 cases of breast carcinoma, 31 cases of intraductal papilloma, and 27 cases of adequate nipple from cancer patients using DNA-chip method.  Results  The HPV-DNA was detected in 8 breast carcinomas (6.5%), but in none of the intraductal papillomas. All detected HPV was high-risk groups; the HPV-18 and HPV-70 were found in each two cases and each one cases HPV-16, 31, 56/58 and 59. In one case of nipple, both low-risk (HPV-62) and high-risk (HPV-18) group HPV-DNA was obtained. The papillary carcinomas and the invasive ductal carcinomas with adjacent intraductal papillomas showed slightly increased incidence (11% vs. 3-4%), however, there was no significant difference. No correlation between the presence of HPV-DNA and specific prognostic predictors for the disease outcome was observed.  Conclusions  Our results suggest that the presence of high-risk group HPV in the breast might be related to breast carcinogenesis, especially papillary phenotype. Further studies are warranted.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3086.
Mouse mammary tumor virus-related sequences in Mus musculus genome and human breast cancer tissues.
Authors: Lushnikova AA , Lyubchenko LN , Parokonnaya AA , Peredereeva EV , Polevaya EB
Published: December 2010

Abstract #3087

Background: Mouse mammary tumor virus is the causative agent for breast cancer (BC) in susceptible mouse lines. MMTV –homologous sequences were detected in breast carcinoma tissue DNA samples from 14-75% BC patients in Mexico, China, USA, Australia and Tunis. However, the sequences weren't found in Japanese, Austrian, English and some other human populations. Earlier, we have found the env MMTV –homologous sequences in BC tissues and peripheral blood lymphocyte DNA samples in 39-42% sporadic and 52% familial BC as well as in 64% of BC during pregnancy and/or lactation. These population differences in MMTV-related retrovirus frequencies might associated with geographic distribution of Mus musculus sp.domesticus – native MMTV reservoir. Material and methods: To demonstrate if wild commensal mice species are MMTV carriers we investigate 11 mice ( 3 males, 8 females) related to Mus musculus sp.domesticus from Moscow region (Russia) using specific PCR and RT-PCR followed by PCR products subcloning in pGEM-T vector and sequencing. A gp52 and ITAM-coding areas of the env MMTV gene, significant for MMTV infection and epithelial cells transformation , as well as a Sag-coding area of 3'LTR were analyzed. MMTV superantigen (Sag) – mediated amplification of MMTV in lymphoid cells is required for efficient viral transformation and dissemination in the mammary gland. Results: The sequences homologous to these functionally significant MMTV genome areas were detected in the DNA samples from mouse liver, timus and peripheral blood. In 63% (7/11) animals analyzed the sequences were expressed. The sequences homology with MMTV genome (C3H strain) according BLAST was 93-96%; homology with human MMTV- related provirus detected in BC patients was 86-95%. Recently MMTV-induced human epithelial cell transformation and important role of ITAM-coding area of the env MMTV gene was demonstrated in vitro. Conclusion: MMTV-related sequences were found in wild commensal mice, Mus musculus sp.domesticus, from Moscow region. In 60% cases these sequences, homologous to functionally significant env- and Sag-coding virus genome regions were expressed. Preliminary data support the possibility of the horizontal MMTV transmission from mice to humans, except of vertical one from mother to children.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3087.
Is there consensus in the definition of endpoints in metastatic breast cancer?.
Authors: Saad ED , Katz A
Published: December 2010

Abstract #3102

Objective: Progression-free survival (PFS) is defined as the time between treatment initiation and tumor progression or death from any cause, with censoring of patients who are lost to follow-up. Time to tumor progression (TTP) is theoretically different from PFS in that the event of interest is only disease progression. Both PFS and TTP have been considered as appropriate endpoints in drug development, but the extent to which investigators agree on their definition is unknown. We therefore assessed the recent literature regarding the consistence of the definition of PFS and TTP when used as primary endpoints in advanced breast cancer.  Methods: We searched PubMed using the medical subject headings “breast neoplasms” and “drug therapy”, limiting the search to phase III trials on systemic antineoplastic therapies published between January 1, 2000, and December 31, 2007 in one of ten leading medical journals in the field (Annals of Oncology, Breast Cancer Research and Treatment, British Journal of Cancer, Cancer, European Journal of Cancer, Journal of Clinical Oncology, Journal of the National Cancer Institute, Lancet Oncology, The Lancet and The New England Journal of Medicine). We excluded randomized phase II trials, factorial trials, studies on high-dose chemotherapy, papers reporting combined analyses of two or more separate trials, and companion studies on correlative biology or prognostic factors.  Results: The search yielded 59 trials enrolling a total of 23,371 evaluable patients in 122 treatment arms. PFS was the primary endpoint in 14 cases, and TTP in 21 when all treatment lines and modalities were considered (response rate was used in 20 cases, and overall survival in only one). For first-line chemotherapy trials (N=24), PFS and TTP were used as primary endpoints in 5 and 7 cases, respectively. In 5 of the 21 trials using TTP as the primary endpoint, no definition of this endpoint was reported in the article. Analysis of the other 16 cases showed that progressive disease was always considered an event in TTP analysis. However, in 13 of these cases, death (either from breast cancer or from any cause) was also counted as an event. The definition of PFS was reported in the article in 13 of the 14 trials using this primary endpoint. In all cases, the events of interest in Kaplan-Meier analyses included both progressive disease and death. In some cases, both terms (PFS and TTP) were even used to denote the same endpoint in the same paper.  Conclusion: Our review suggests that investigators are frequently using PFS and TTP interchangeably in metastatic breast cancer. Such use of terms may lead to confusion when results of different trials are evaluated in perspective, and standardization of the definitions seems therefore in order.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3102.
Feasibility trial of electro-acupuncture for aromatase inhibitor related arthralgia in breast cancer survivors.
Authors: Mao JJ , Stricker CT , Farrar JT , Xie SX , Bowman MA , Bruner DW , Pucci D , Han X , DeMichele A
Published: December 2010

Abstract #3105

Background: Arthralgia affects postmenopausal women receiving aromatase inhibitors (AI) for breast cancer. Given the existing evidence for electro-acupuncture (EA) for treatment of osteoarthritis in the general population, this study aims to establish the feasibility of studying EA for treating AI-related arthralgia.  Patients and Methods: Postmenopausal women with stage I-III breast cancer with joint pain related to AIs were enrolled in a pilot single arm trial of acupuncture. Acupuncture was provided twice a week for 2 weeks followed by 6 weekly treatments (total of 10 treatments over 8 weeks). Manualized protocol was based on Chinese medicine diagnosis of “Bi” syndrome with eletro-stimulation of needles around the painful joint(s). Pain severity of the modified Brief Pain Inventory was used as the primary outcome. Joint stiffness and Joint interference were secondary outcomes. Patient Global Impression of Change (PGIC) was used to assess clinical relevance. Fatigue and anxiety were also evaluated. Paired-t tests were used for analysis.  Results: Twelve women were enrolled and all provided data for analysis. From baseline to the end of intervention, patients reported improvement in pain severity (5.3 to 1.9), stiffness (6.9 to 2.4), and joint symptom interference (4.7 to 0.8), all P<0.001; 11/12 reported joint symptoms “very much improved” based on PGIC . Subjects also reported significant decrease in fatigue (4.4 to 1.9, p=0.005) and anxiety (7.1 to 4.8, p=0.01). One subject withdrew from interventions due to an adverse event (herpes zoster) thought to be unrelated to acupuncture. Two subjects reported grade 1 self-limiting pain associated with acupuncture. No infection or development or worsening of lymphedema was observed.  Conclusion: EA is a potentially safe and effective treatment for AI-related arthralgia; thus, a randomized controlled trial is warranted to establish the short term and long term efficacy and safety of EA in breast cancer survivors.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3105.
Factors that influence seeking second opinions, patient satisfaction, and education in breast cancer care: an internet-based study.
Authors: Lund M , Bramley AM , Iyengar RG , Petersen J , Wood WC , Gabram SS
Published: December 2010

Abstract #3107

Purpose: To examine factors associated with seeking second opinions, patient satisfaction, and education among a recently diagnosed internet-based breast cancer population. Methods: In 2007, 6970 of the 90,426 internet-registered female breast cancer patients completed an internet-based survey, developed jointly by members of the Department of Surgical Oncology at Emory University and the educational staff at the Healthcare business of Thomson Reuters, formerly Nexcura. After excluding caregivers (n=205), those not within 5 years of diagnosis (n=962) or for whom treatment information was missing (n=40), we analyzed 5763 patients. Chi-square tests were used to assess system characteristics and patient demographics by their second opinion, satisfaction, and informed status. Patient satisfaction was collapsed as low (1-3), moderate (4-6), or high (7-10). How informed patients considered themselves was combined into 3 categories: well-informed (well or very well informed), somewhat informed and uninformed (somewhat or very uninformed). Results: The majority of the 5763 patients were between ages 40 and 59 when diagnosed (75.43%), Caucasian (92.96%), currently married (76.33%), had a household income ≥ $50,000 (60.92%) and at least a 4-year college education (55.78%). Stage I and II cancers comprised 36.61 and 35.71% respectively. Over one-third (n=2039) sought a second opinion. Factors significantly associated with seeking a second opinion were higher socioeconomic or education status, feeling informed, receiving the initial diagnosis from a primary care physician or private community hospital, close proximity to the biopsy location, and less satisfaction with the initial biopsy experience. Patients highly satisfied with their second opinion (87.35%) were more likely to refer others (96.52%), use the second opinion facility for the next treatment (63.90%), and to not seek additional opinions (75.29%). Facility options and initially being treated with surgery or systemic therapy predicted high satisfaction with initial treatment. Medical oncologists were the most frequently cited primary source of breast cancer education (37.81%), followed by surgeons (30.57%), and the internet (12.77%). About 20% who cited these sources considered themselves somewhat or very uninformed. Conclusions: Women who seek information via the internet rely primarily on medical professionals for their breast cancer education. Factors related to the initial biopsy affect the likelihood of patients seeking a second opinion, satisfaction with second opinions can influence choices regarding the ensuing treatment steps, and factors associated with initial treatment influence patient satisfaction. Probing the issues underlying these findings could improve care for all.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3107.
BRCA testing in underserved women: a qualitative study of intepretations and impacts.
Authors: Joseph G , Wilcox C , Luce J , Beattie MS
Published: December 2010

Abstract #3109

Background: As BRCA testing becomes more available to underserved populations, it is important to understand how the BRCA testing process is interpreted by these patients and their families. It is also essential to study the medical and psycho-social effects of BRCA testing for underserved populations. This study aims to explore the impact of BRCA results and the process of BRCA testing in underserved women.  Methods: Underserved women at San Francisco General Hospital (SFGH) who underwent BRCA testing received individual, in-depth, 1-2 hour, semi-structured interviews by a medical anthropologist. Interviews addressed: personal background, initial referral, delivery of test results, understanding of test results, sharing of test results and impact of testing and results on the patient and her family. Interviews were transcribed verbatim, coded using a qualitative data analysis system (Atlas-ti), and analyzed by two authors. Participants were chosen to include the diverse range of patients at SFGH.  Results: Of 130 women at SFGH who received BRCA testing, 8 to date have been interviewed (age 35-56). Four had breast cancer. BRCA results include: 4 negative, 2 variant, and 2 positive. Six participants were white; 2 African American. Preliminary data analysis shows that the idea of genetic testing and counseling for breast cancer was completely new at the time of referral for most participants. Participants with breast cancer wanted testing for their children and siblings. "I definitely wanted to know…so that we would have information as far as my son and my sister, and we would have a heads up and know, because early detection is what saved my life." Participants who did not have cancer but who perceived a lot of cancer in the family were interested in and reassured by the genetic counseling/testing experience. “I've been held captive with the word “cancer” all my life." Those with inconclusive results (uninformative negative and variant) had a limited understanding of the implications of their test results for their cancer risk and that of their relatives and struggled with what to communicate to family members. An affected women with negative results said, "With my sister …we have the same parents, but if mine came back negative, I don't know if that means she's totally out of the dark for herself." Participants consistently had positive feelings about their experience with genetic counseling and testing.  Conclusions: Given our sample size and methodology, it is not appropriate to generalize. But, this preliminary data suggests that many variables relate to individual understanding and interpretation of BRCA results including: cancer diagnosis and health status at time of testing; BRCA result; experience with counseling; and time since counseling and BRCA testing to process and interpret results.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3109.
Incidence of postmenopausal symptoms and current mamagement: a survey of 260 breast cancer patients.
Authors: Petrella T , Fralick J , Dranitsaris G , Clemons M , Gandhi S , Verma S , Dent R
Published: December 2010

Abstract #3117

Background: The advent of newer and more efficacious adjuvant treatments has allowed women to live longer without cancer recurrence. However these treatments often prematurely induce menopause, worsen menopausal symptoms and may have long-term effects on postmenopausal health. The objectives of this study were to examine the incidence of post-menopausal symptoms and how such symptoms are currently being managed outside of a clinical trial setting, in order to better facilitate patient care. Methods: A self-administered questionnaire was completed by 260 postmenopausal breast cancer patients assessing treatment-induced side effects, how patients were monitored and patient follow-up. Descriptive statistics were used to describe results. Parametric and non-parametric inferential statistics were used in an exploratory analysis to compare post-menopausal symptoms between patient subgroups. Results: Of the 260 patients, 48% percent received endocrine therapy, 17.7% received chemotherapy and 26.2% were not on any therapy at the time of this study. The most common reported symptom was hot flashes (49.2%). Other common reported symptoms were difficulty sleeping (44.6%), weight gain (35.9%), memory problems (33.1%), and vaginal dryness (32.7%). Statistically significant correlations were identified between the use of aromatase inhibitors and the development of hypercholesterolemia and osteopenia. In contrast, the use of tamoxifen was significantly associated with the occurrence of vaginal symptoms such as dryness, itching and bleeding. Majority of patients were also monitored by their family physician with cholesterol monitoring (84%) and bone densitometry (68.1%) either yearly or every two years. Though most patients (83.5%) felt that their medical oncologist should monitor their breast cancer, they preferred to discuss their endocrine symptoms with their family physician (57.9%). Conclusions: The incidence and association of symptoms reported were consistent with the current literature. The management of long-term consequences of breast cancer therapies is going to remain a major part of our role as medical oncologists. However, involvement of family physicians in management of symptoms seems to be preferred by many patients.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3117.
A phase I, dose escalation study of lapatinib in combination with carboplatin, paclitaxel, with and without trastuzumab in patients with metastatic breast cancer.
Authors: Storniolo A , Rubin P , Magrinat G , Parker B , Rush-Tayler A , Sheidler V , Aranjo S , Shaw C , Eldreth N , Lott G , Brechlin J , Loftiss JI , Fleming RA , Weber BL
Published: December 2010

Abstract #3121

Background: Lapatinib is a selective and highly potent dual, competitive inhibitor of erbB1 and erbB2 tyrosine kinases with clinical activity in erbB2-positive metastatic breast cancer (MBC). The combination of carboplatin, paclitaxel, and trastuzumab has been shown to have significant clinical activity in MBC as well as in the adjuvant setting. Given the synergy of dual inhibition with trastuzumab and lapatinib observed in both the preclinical and clinical settings, we assessed the feasibility, safety, and early clinical activity of paclitaxel, carboplatin, lapatinib with and without trastuzumab in patients (pts) with MBC.  Methods: MBC pts previously untreated with trastuzumab or cytotoxic chemotherapy for metastatic or locally recurrent disease were enrolled into either Group (Grp) A (erbB2 positive) or B (erbB2 positive or negative). Escalating doses of lapatinib (planned range of 750-1500 mg/d) were administered in combination with (Grp A) or without (Grp B) trastuzumab (4 mg/kg followed by weekly 2 mg/kg infusions). Paclitaxel (80 mg/m2) and carboplatin (AUC 2 mg/ml*min) were administered on days 1, 8, 15 with cycles repeated every 28 days. Starting doses of lapatinib were 750 mg in Grp A and 1000 mg in Grp B. A standard 3 + 3 Phase I design is being used until the optimally tolerated regimen (OTR) dose level is determined. An additional 14 - 17 pts will be enrolled into each grp at the OTR dose level to further assess safety and tolerability.  Results: Fourteen pts (Grp A n=8, Grp B n=6) have been enrolled in the study (median age 42 yrs, range 27-66). A median of 5.5 cycles (range 4-17) in Grp A and 3.5 (range 1-7) in Grp B have been administered. All pts had at least one adverse event (AE). In Grp A, grade 3 toxicities include neutropenia (50%), diarrhea (38%), rash (25%), vomiting (13%), hypokalemia (13%), and syncope (13%). No grade 4 toxicities were reported. In Grp B, grade 3 toxicities include fatigue (33%), hyponatremia (17%), menorrhagia (17%), dermatitis (17%), and rash (17%). One pt (in Grp B) had grade 4 neutropenia. No febrile neutropenia was observed. In Grp A, there was one DLT (Gr 3 diarrhea) at lapatinib 1000 mg. In Grp B, one DLT (Gr 4 neutropenia) at lapatinib 1000 mg has been observed. Clinical activity to date includes 8/8 objective responses in Grp A, (1 CR, 7 PR) and 2/6 objective responses (2 PR) in Grp B (all pts in Grp B were erbB2 negative). Dose escalation continues in both grps.  Conclusions: Lapatinib may be administered safely in combination with carboplatin, paclitaxel, with and without trastuzumab at known effective doses for each. Clinical activity has been observed.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3121.
Antitumor activity, and antiangiogenic activity of nanoparticle albumin-bound nab-rapamycin in combination with nab-paclitaxel.
Authors: Desai N , Ran S , Volk L , Stutzman A , D'Cruz O , Trieu V
Published: December 2010

Abstract #3125

Background: Rapamycin inhibits downstream signals from the mammalian target of rapamycin (mTOR), a known kinase member of a signaling pathway that promotes tumor growth. Rapamycin's poor aqueous solubility and poor chemical stability have limited its development as an intravenous (IV) anticancer agent. Nab-rapamycin utilizes the albumin-bound technology to allow for IV administration of rapamycin and has demonstrated dose-linear pharmacokinetics and safety up to 90 mg/kg with effective antitumor activity at 40 mg/kg against a human panel of tumor xenografts. This study investigated the efficacy of combined therapy with nab-paclitaxel (Abraxane®) utilizing invasive human breast (MDA-MB-231) and colon (HT29) cancer xenograft models.  Material and Methods: Xenograft transplants using luciferase-tagged MDA-MB-231 cells were implanted into mammary fatpad of SCID mice and allowed to reach 460 mm3 in size prior to IV administration of saline (vehicle, n = 9); nab-rapamycin, 3x wkly for 2 wks at 40 mg/kg (nab-rap-2W; n = 8); nab-rapamycin, 3x wkly for 4 wks at 40 mg/kg (nab-rap-4W; n = 8); Abraxane, qdx5 at 30 mg/kg (ABX; n = 8); nab-rap-2W + ABX (n = 9); or nab-rap-4W + ABX (n = 8). HT29 xenografts were also treated with nab-rap-4W (n = 8) and nab-rap-4W + ABX (10 mg/kg, qdx5, IP, n = 8). The in vivo antiangiogenic effect of nab-rapamycin was evaluated using the standard in vivo chick chorioallantoic membrane (CAM) assay with 3-day old embryos (n = 18).  Results: Relative to vehicle controls, nab-rap-2W (P < 0.00011), nab-rap-4W (P < 0.0001), and ABX (P < 0.0001) were effective against MDA-MB-231 tumor xenograft models with tumor growth inhibition (TGI) of 60%, 66%, and 73% respectively. Additive antitumor effects were observed with combination of nab-rapamycin + ABX with TGI of 81% and 86% for nab-rap-2W + ABX and nab-rap-4W + ABX groups, respectively. For HT29 tumors, the combination of ABX and nab-rapamycin also showed greater TGI (89%) compared to nab-rapamycin alone (81%). In the chick CAM assay, nab-rapamycin demonstrated antiangiogenic efficacy at doses of 10 µg and above without affecting embryo viability.  Conclusions: Combination therapy of nab-rapamycin and Abraxane was more effective at inhibiting breast and colon xenograft tumor growth than single therapy of either drug. The enhanced antitumor activity seen with combined nab-rapamycin-Abraxane may in part be due to the observed antiangiogenic activity of nab-rapamycin.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3125.