bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract P2-06-03: A Polymorphic AAAG Repeat in the Estrogen Receptor-Related-Gamma Gene May Represent a Breast Cancer Predisposition Biomarker
Authors: Garner HR , McCormick JF , Li L-S , McIver LJ , Bubb VJ , George AC , Boothman DA , Quinn JP , Galindo C. 
Published: April 2011

Abstract
Background: There is a strong genetic component to breast cancer, which is the most common neoplasm in women; however current risk markers are few, accounting for less than 10% of breast cancer cases. This means that the majority of familial breast cancers remain unexplained. Our laboratory has studied microsatellite polymorphisms for many years, and we developed techniques to assay these understudied regions of the genome en masse and individually via shot-gun methods to rapidly identify those that are likely to be polymorphic and therefore potentially contribute to phenotype.
Material and Methods: Using these novel approaches, we identified a polymorphic AAAG microsatellite repeat in the estrogen-related receptor gamma (ERR-γ) that is expanded in -10% of the general population. We genotyped over 300 individuals and found a longer allelic version (13+ repeat copies) in 14.3% of breast cancer patients, compared to only 4.8% in cancer-free individuals. We computationally identified 22 transcription factors that could bind directly to this AAAG repeat and the surrounding region. We hypothesized that the AAAG-containing region might serve as a promoter for ERR-y.
Results: We found a statistically significant number of breast cancer patients with the expanded AAAG allele, and preliminary experiments confirm that the AAAG-containing region of ERR-γ does indeed drive reporter gene expression in estrogen receptor positive (ER+) MCF-7 breast cancer cells. This was not the case for the ER-breast cancer cells (MDA-MB-231) we also examined. Our initial assessments also revealed that SKBR-3 breast cancer cells are naturally heterozygotic for the long and short allelic versions of the AAAG repeat. Our ongoing studies involve knockdown of transcription factors in MCF-7 cells that abrogate the endogenous expression of ERR-γ.
Discussion: The role of microsatellites in cancer is well defined for colon cancer, but few studies have been conducted to examine the contribution of these simple sequence repeats in breast cancer. We discovered a polymorphic AAAG repeat in the ERR-γ gene, and our studies indicate that a longer version of this repeat is more prevalent in the genomes of breast cancer patients. Based on our assessment, this allele carries a 2.98 relative risk for the development of breast cancer. The higher incidence of this putative biomarker in breast cancer patients may be a result of altered ERR-γ expression, as the AAAG-containing sequence can drive reporter expression. If the frequency of this potentially predictive marker is sustained in a larger population, and the mechanism by which it confers the cancer phenotype can be identified, it may contribute substantially as a biomarker offering surveillance, prophylactic surgery, and chemoprevention options to patients.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-06-03.
Abstract P2-06-09: Mucin4 Is Associated with the Loss of Estrogen-Receptor-α in Breast Cancer
Authors: Chen AC , Migliaccio I , Gilcrease M , Osborne CK , Schiff R. 
Published: April 2011

Abstract
Data suggests that breast carcinomas that overexpress the HER2 oncoprotein are more resistant to endocrine treatments such as tamoxifen (Tam) or estrogen deprivation (ED) via aromatase inhibitors. To investigate possible mechanisms of endocrine resistance in vivo, we performed a gene microarray analysis on estrogen receptor-(ER)+, HER2-overexpressing xenograft tumors that are de novo resistant to tamoxifen treatment and acquire resistance to ED therapy. A large number of genes were upregulated, including several members of the mucin family of genes. This corroborated our finding from histological staining of the resistant tumors that indicated striking increases of mucin vacuoles when compared to sensitive tumors. These vacuoles were located mostly intracellularly and stained positive for mucins with mucicarmine. We were particularly interested in one particular mucin, mucin4 (MUC4) because previous studies have suggested its role in stabilizing and enhancing HER2 signaling. Quantitative realtime PCR confirmed the microarray results and showed that there was an approximately 156-fold increase in MUC4 transcript between the ED-sensitive and ED-resistant tumors, with a 65-fold increase between the early Tam and late Tam-resistant tumors. Immunohistochemistry confirmed that this upregulation in these two treatment groups was present also at the protein level. Furthermore, western blot analysis of these tumors demonstrated that resistant tumors have downregulation of ER protein and its downstream effectors with corresponding increase in total HER2 protein levels. These tumors have seemingly shifted away from the ER pathway to signaling via the growth factor signaling pathway. Preliminary experiments where MUC4 protein was stably overexpressed in ER+, HER2-overexpressing cells model these results in vitro with a downregulation of ER protein and downstream effectors, showing that ER expression and activity are affected. Furthermore, immunohistochemical analysis of 73 primary human invasive breast carcinomas suggests that MUC4 is associated with estrogen-receptor negative tumors (P=0.05). This clinical data validates the preclinical studies for investigating a possible mechanism for the loss of ER, and suggest MUC4 as an inviting biomarker for endocrine treatment and a potential therapeutic target for endocrine resistant breast cancer.
Crosstabulation of MUC4 and ER

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-06-09.
Abstract P2-06-12: HER2 mRNA Expression Is Influenced by Estrogen Receptor Status and PI3K Mutational Status
Authors: Bloom KJ , Choppa P , Kyshtoobayeva A , Barry T , Goldstein N. 
Published: April 2011

Abstract
Molecular profiling has suggested that ER+/HER2+ breast cancer is a distinct entity from ER-/HER2+ breast cancer and confers a worse prognosis in systemically untreated patients. It has recently been reported that genes associated with PI3K/AKT pathway activation predict pathologic complete response in patients receiving trastuzumab-chemotherapy in ER+/HER+ but not in ER-/HER2+ tumors. Past studies have indicated that 30-40% of breast cancers harbor a PI3K mutation, predominantly in exons 9 and 20. We analyzed 100 HER2+ breast cancers stratified by ER status to confirm the differing level of HER2 mRNA expression relative to ER status and to determine the association, in any, to the presence of a PI3K mutation.
Methods: Fifty ER+ and 50 ER-breast cancers previously assessed as HER2+ (HER2:CEP-17 ratio ranging from 2.40-16.20, PathVysion Kit, Abbott) were pulled from the archives. ER was assessed by IHC, (6F11, NovaCastra) using a clinically validated method in accordance with the new CAP/ASCO guidelines. Molecular analysis was performed on paraffin embedded tissues. Tumor areas of interest were identified and selectively removed from the section. RNA and DNA were isolated from the collected tissue. Real-time quantitative RT-PCR was used to evaluate the expression of the HER2 gene from the RNA fraction. The expression values were calculated as a ratio of HER2 to the reference gene. The DNA was added to an allele specific PCR to assess 7 of the most common mutations in exons 9 and 20 of the PI3K gene. All data was generated on an AB 7900 HT real-time platform.
Results:
Quantitative HER2 mRNA Results
Discusssion: The level of HER2 mRNA expression differs significantly based on the expression of ER. This is further accentuated by the presence of a PI3K mutation, increasing the level of HER2 mRNA expression is ER-patients and decreasing the level of HER2 mRNA expression in ER+ patients. This observation needs to be further explored and may have profound implications, if as current data suggests, the subset of patients most responsive to trastuzumab therapy are the ER+, PI3K activated tumors.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-06-12.
Abstract P2-06-15: The Use of ADH-5 Stain as a Surrogate Marker for Molecular Classification of Basal and Luminal Breast Cancers
Authors: Turner BM , Yeh I-T 
Published: April 2011

Abstract
BACKGROUND: Immunohistochemical (IHC) analyses of protein expression have recently been used as surrogate assays for the molecular classification of breast cancers. Specifically, ER+/PR+/HER2- tumors are typically considered luminal-type breast cancers, ER-/PR-/HER2+ tumors equate to HER2 over-expressing tumors, whereas ER-/PR-/HER2- (triple negative, TN) tumors are basal-like breast cancers. A newly available cocktail of antibodies called ADH-5 allows for the simultaneous evaluation of both luminal and basal keratins. In this study, we examine the expression of luminal and basal keratins in breast cancers stained with ADH-5, particularly in a subgroup of basal keratin positive tumors. METHODS: All invasive breast cancers from 12/2009-6/2010 in a single pathology laboratory were studied by ADH-5 antibody cocktail consisting of two luminal keratin (LK) markers (CK7 and CK18), and two basal keratin (BK) markers (CK5 and CK14), as well as a myoepithelial marker, P63 (Biocare, Concord, CA). ER, PR, HER2 and Ki-67 were also evaluated by IHC and scored in all tumors. The group included 81 breast cancers and 3 metastatic tumors from the breast. ADH-5 staining was evaluated in areas of invasive carcinoma, and intensity and proportion of staining by BK and LK were scored. Mean statistics and ratios were evaluated and compared for each of the scored stains using the student t-test (stt) and chi squared analysis (cs), respectively.
RESULTS: Of the 84 cancers, 20 (24%) showed some staining for BK, and 63 (75%) showed only LK staining. One case (1%) showed no staining for either BK or LK. Of the BK+ cases, 19/20 (95%) showed some degree of LK staining as well. Only one BK+ tumor lacked luminal keratin positivity (5%). Co-expression both BK and LK was seen in the same cells, though many cells were more strongly positive for one keratin type. The BK+ tumors were significantly more likely to be TN (p = 0.5, cs), and all TN tumors showed some BK staining. Four ER+/PR+/HER2- tumors expressed low levels of BK; two additional ER+/PR+/HER2+ tumors also expressed BK. ER-, PR-and TN tumors tended to show a significantly greater proportion of BK staining and decreased amount of luminal staining than ER+, PR+ and non-TN tumors.
DISCUSSION: ADH-5 stain demonstrates co-expression of luminal keratins in basal keratin positive breast cancers, including all triple negative breast cancers in our study. In addition, some ER+/PR+/HER2- tumors and ER+/PR+/HER2+ (considered luminal A and B, respectively, by current usage of ER/PR/HER2 as surrogate markers) actually express basal keratins, bringing up the issue of whether these tumors should be considered luminal or basal-like. The ADH-5 stain may be helpful as a surrogate molecular marker for the classification of breast cancers.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-06-15.
Abstract P2-07-07: Ehm2 Influences the Aggressiveness of Breast Cancer Cells through Regulation of MMP-9 Expression, and Aberrant Expression of Ehm2 Correlates with Disease Progression in Breast Cancer
Authors: Yu H , Ye L , Zhang Y , Mansel RE , Jiang WG. 
Published: April 2011

Abstract
Background. Ehm2 is a member of NF2/ERM/4.1 superfamily and has been indicated in cell membrane/cytoskeletal interaction and cellular motility. In the present study, we investigated the expression pattern of Ehm2 in breast cancer and the impact of Ehm2 on the biological behavior of breast cancer cells.
Methods. A cohort of breast cancer specimens (normal, n=33; cancer, n=127) was tested for Ehm2 expression, using both quantitative real time PCR and immunohistochemical staining. A hammerhead ribozyme transgene was employed to knockdown Ehm2 expression in breast cancer cells. The effect on growth, cell matrix adhesion, motility and invasion by Ehm2 knockdown was then examined using in vitro assays. Results. Immunohistochemical staining and quantitative real time PCR revealed an increased expression of Ehm2 in breast cancer. High levels of Ehm2 transcripts correlated with disease progression, metastasis and poor prognosis. Disease free survival of the patients with lower level of Ehm2 was 135.8 (125.1-146.5, 95%CI) months, significantly longer compared with 102.5 (78.7-126.4, 95%CI) months of patients with higher level of Ehm2 expression, P=0.039. Knockdown of Ehm2 had inhibitory effects on both in vitro growth and invasion of breast cancer cells. Flow cytometric analysis showed that knockdown of Ehm2 resulted in an increase (&gt;10%) of apoptotic cells overthe control cells. Furthermore, it was shown that knockdown of Ehm2 significantly decreased the protein and mRNA expression of matrix metalloprotease MMP9. Zymograhpy revealed a reduced activity of MMP9 in breast cancer cells after knockdown of Ehm2.
In conclusion, Ehm2 is able to promote invasion of cancer cells via regulating MMP9, and can also protect them from apoptosis. This may have important implication in the correlation between increased Ehm2 expression and poor prognosis and metastasis in breast cancer.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-07-07.
Abstract P2-08-01: XPD Single Nucleotide Polymorphisms and Copy Number Variation in Puerto Rican Women and Breast Cancer Risk
Authors: Pacheco-Torres AL , Colon C , Matta J , Dutil J. 
Published: April 2011

Abstract
Background: The nucleotide excision repair (NER) pathway is the primary mechanism for the repair of bulky and helical distorting adducts. Previous studies suggest that polymorphisms in the XPD gene may contribute to the susceptibility of an individual to develop cancer. However, this data have not been validated in the population of Puerto Rico and most studies were limited to assessing the role of single nucleotide polymorphisms (SNPs). Copy number variations (CNVs) are segments of DNA that have a variable copy number compared to a reference genome. Our objective was to characterize the role of the SNPs and CNVs in the XPD gene and the susceptibility for breast cancer in Puerto Rican women. Material and Methods: Extracted DNA from healthy controls (n=252) and breast cancer patients (n=152) was used to perform TaqMan allelic discrimination for Single Nucleotide Polymorphisms (SNPs) rs13181, rs1799793 and rs238407 of the XPD gene. The XPD genomic region was screened for the presence of copy number variations using a Taqman CNV genotyping assay in exon 10 of the gene.
Results: Interestingly, the control population was in Hardy-Weinberg disequilibrium for the SNPs rs1799793 and rs238407, suggesting the presence of copy number variation (CNV) in the XPD genomic region. In our study population, we found that the copy number around XPD ranges from one copy to more of 10 copies. The distribution of the CNV genotypes between controls and cases was statistically significant (p=0.021). Individuals carrying zero copy of the gene were more likely to develop breast cancer than individuals with more than two copies (Odds ratio: 2.6, 95% confidence interval 5.134 — 1.336, P&lt;0.005). Significance: This study is expected to contribute to the identification of individuals that are at higher risk of breast cancer, prior to the development of the disease. This will aid in prevention and treatment decisions in an individual's breast cancer management strategies.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-08-01.
Abstract P2-09-01: Serial [18F] FDG-PET after the 2nd Cycle of Preoperative Chemotherapy Is Predictive for Pathological Complete Response in Stage II/III Breast Cancer
Authors: Jung S-Y , Kim S-K , Kwon Y , Kim E-A , Ko KL , Park IH , Lee KS , Kang KW , Noh D-Y , Shin SH , Jeong JS , Lee S , Kim SW , Kang H-S , Ro J. 
Published: April 2011

Abstract
Purpose: One of substudies of the prospective trials aimed to evaluate the usefulness of serial [18F] 2-fluoro-2-deoxy-D-glucose-positron emission tomography ([18F] FDG-PET) for predicting pathological complete response (pCR) in stage II/III breast cancer with preoperative chemotherapy (PST).
Methods: Serial PET was undertaken in 57 breast cancer patients enrolled in three different neoadjuvant trials: 35 patients from a phase II study with paclitaxel/gemcitabine/trastuzumab with ClinicalTrial.gov NCT 00532857, 9 patients from a phase Ib study with paclitaxel/gemcitabine/lapatinib with ClinicalTrial.gov NCT 01133912, and 13 patients from a phase Ib with paclitaxel/gemcitabine/sunitinib with ClinicalTrial.gov NCT0 1070706. All patients received 6 cycles of PST followed by surgery and radiotherapy. We assessed the peak standardized uptake value (SUVp) in the primary tumor at the baseline and after the 2nd cycle (37 patients) or after completion (20 patients) of 6 cycles of PST, and calculated the reduction rate (RR) of the SUVp. Pathological response was classified into pCR and non-pCR. To compare the mean of SUVp and RR of SUVp between different response groups, two-way tables and chi-square tests were used
Results: Fifteen (40.6%) of 37 patients who took repeat PET after the 2nd PST and 15 (75%) of 20 patients after completion of PST achieved a pCR with overall pCR rate of 52.6% in the primary tumor. In patients with repeat PET after the 2nd PST, post-treatment SUVp and RR of the SUVp in primary tumors were significantly different by the pathological response (post-treatment SUVp, 1.54 ± 0.63 in pCR vs 2.54 ± 1.06 in non-pCR, P=0.002; RR of the SUVp, 79.2% ± 11.9% in pCR vs 68.9% ± 15.4% in non-pCR, P=0.03). However, in patients with repeat PET after completion of PST, there were no statistical differences of these values (post-treatment SUVp, 1.09 ± 0.63 in pCR vs 1.29 ± 0.36 in non-pCR, P=0.42; RR of the SUVp, 83.7% ± 14.0% in pCR vs 67.5% ± 21.1% in non-pCR, P=0.17)
Conclusions: This study demonstrated that repeat PET after the 2nd cycle of PST, not after completion of PST could predict pCR in stage II/III breast cancer with preoperative chemotherapy. Acknowledgement NCC Grant #0910320.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-01.
Abstract P2-09-02: Validation of a Novel Staging System for Disease-Specific Survival in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy
Authors: Mittendorf EA , Jeruss JS , Tucker SL , Kolli A , Newman LA , Gonzalez-Angulo AM , Buchholz TA , Sahin AA , Cormier JN , Buzdar A , Hortobagyi GN , Hunt KK. 
Published: April 2011

Abstract
Purpose We previously described a novel breast cancer staging system for assessing prognosis after neoadjuvant chemotherapy based on pretreatment clinical stage (CS), estrogen receptor status (E), grade (G) and post-treatment pathologic stage (PS). This CPS+EG staging system assigned and summed points for each factor, allowing for better determination of breast cancer-specific survival than CS or PS alone. The current study was undertaken to validate this staging system using internal and external cohorts.
Methods We identified 804 patients treated with neoadjuvant chemotherapy at our institution from 2003-2005 who were not part of the original determination of the CPS+EG staging system and an external cohort of 165 patients treated at another institution. Clinicopathologic characteristics, treatment regimens, and patient outcomes were assessed. Outcomes were stratified by CPS+EG score in order to test whether the 5-year disease-specific survival (DSS) in each CPS+EG group was numerically as predicted.
Results The 5-year DSS for the internal cohort was 77% (95% CI: 72-82) at a median follow-up of 3.4 years (range, 03-5.9). The 5-year DSS for the external cohort was 86% (95% CI: 7 -91) at a median follow-up of 4.7 years (range, 0.5-10.5). The ability of the CPS+EG score to distinguish outcomes based on good or poor prognosis was confirmed in both the internal and external cohorts. In both cohorts, application of the CPS+EG staging system facilitated more accurate categorization of patients into prognostic subgroups than CS or final PS as defined by the American Joint Committee on Cancer (AJCC) staging system.
Disease-Specific Survival Outcomes Based on the CPS+EG Staging System
Application of the CPS+EG to all three cohorts combined, demonstrated 5-year DSS ranging from 23% to 99% versus 5-year DSS ranging from 61% to 92% based on presenting CS or 58% to 95% based on post-treatment PS.
Conclusion The current study validates the CPS+EG staging system in independent patient cohorts. We recommend that biologic markers and response to treatment be incorporated into revised versions of the AJCC staging system for patients receiving neoadjuvant chemotherapy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-02.
Abstract P2-09-06: Meta-Analysis of the Decision Impact of the 21-Gene Breast Cancer Recurrence Score in Clinical Practice
Authors: Hornberger J , Chien R 
Published: April 2011

Abstract
Background: The 21-gene Recurrence Score® (RS) is a clinically validated assay that predicts the likelihood of chemotherapy benefit and the risk of distant recurrence for individual patients with estrogen receptor positive (ER+), early stage breast cancer (ESBC). The 21-gene RS is included in the published guidelines of the National Comprehensive Cancer Network and American Society of Clinical Oncology as an adjuvant-treatment decision tool. Recently, university-led studies have reported approximately 17-27% decision impact of 21-gene RS in actual practice. We reviewed the published literature and conducted a meta-analysis of the impact of the 21-gene breast cancer RS on treatment recommendations and decisions in clinical practice.
Method: Published cohort studies that reported the change in the recommendation or actual use of adjuvant chemotherapy (CTX) before and after the RS were included. Patients must be identified as ER+, LN-ESBC. Outcomes evaluated were: treatment decision change from 1) CTX plus hormone therapy to hormone therapy only or 2) hormone therapy-only to CTX plus hormone therapy. Actual treatment change was used when available. Reductions in the relative and absolute CTX use associated with the 21-gene breast cancer RS were computed with Review Manager 5
Version 5.0.24. (Copenhagen: The Nordic Cochrane Centre, the Cochrane Collaboration, 2008).
Results: 7 published studies, with a total of 913 patients were included in the meta-analysis. 62% (566/913) of patients were recommended or received CTX prior to testing with the 21-gene RS. After RS testing, 29% percent (268/913) of patients were recommended or received CTX. The absolute reduction of CTX use associated with RS testing was 30% (95% CI [-40%, -21%]) The relative risk ratio is computed as a ratio, weighted by the sample size of each study, of (1) proportion of patients treated with CTX plus hormone therapy after 21-gene RS and (2) proportion of patients treated with CTX plus hormone therapy before 21-gene RS. The estimated relative ratio in CTX use before and after 21-gene assay is 49% (95% CI [41%, 58%]). One limitation of this analysis is the heterogeneity in the study designs of the published studies. Of the 7 available studies, 1 was a prospective physician survey; 6 were retrospective chart reviews. A second limitation of the study is in the consistency of reported outcomes. 4 studies reported the use of CTX after 21-gene breast cancer RS, whereas the remaining 3 reported the physicians’ treatment recommendations. Lastly, the meta-analysis does not capture the important benefit of the RS for patients who switch from no CTX to CTX when a high RS is obtained. Conclusion: The meta-analysis shows consistent overall reduction in AC with the adoption of the 21-gene breast cancer RS.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-06.