Immunohistochemical Study and Clinicopathologic Correlation of Cox-2 and Her-2 Expression in Colorectal Carcinoma: A 5-Year Retrospective Study

BACKGROUND

Colorectal cancer (CRC) is the fourth most common cancer in Nigeria, and it affects mostly persons in their middle age. In a bid to gain some insight into the molecular characteristics of CRC in our environment, we set out to investigate the expression of COX-2 and HER-2 among Nigerian subjects.

OBJECTIVES

To evaluate the expression of COX-2 and HER-2 and determine their correlation with clinicopathologic parameters in surgically resected histologically diagnosed cases of colorectal cancer.

METHODS

Fifty-three paraffin-embedded tissue blocks of colorectal resections and corresponding patient information were retrieved from the archives of the Anatomic and Molecular Pathology Department of Lagos University Teaching Hospital. A 4-micron slide section was obtained from each specimen and immunohistochemistry for COX-2 and HER-2 expression was performed.

RESULTS

Mean age of cases was 53.9years with an almost equal M:F ratio of 1.12:1. Half of the cases were moderately differentiated adenocarcinoma and 17% were high grade tumors. Eighty three percent of the tumours showed positive cytoplasmic COX-2 expression and extremely low membranous HER-2 positivity was observed in 2%. There was no significant correlation between COX-2 expression and age, gender, tumour location, tumour size, depth of invasion or lymph node status. However, COX-2 expression revealed a significant correlation with tumour grade (p= 0.013).

CONCLUSION

This study detects a high COX-2 and low HER- 2 expression in colorectal cancer using immunohistochemistry, suggesting a possible role for COX-2 in CRC pathogenesis. This report should trigger further investigations of both markers vis-à-vis the management of CRC in our environment.

Abstract P1-08-05: Type 2 diabetes and survival outcomes among a multi-ethnic cohort of breast cancer patients

BACKGROUND: With increasing prevalence of type 2 diabetes, it has become one of the common comorbidities among breast cancer patients. Few contemporary studies have examined the effect of preexisting diabetes on survival outcomes in breast cancer patients. Furthermore, both breast cancer mortality and diabetes prevalence are higher in African American women compared to Caucasian women, yet data on whether diabetes can explain racial disparity in breast cancer mortality is scarce.

OBJECTIVE: To compare clinopathological characteristics and survival outcomes between breast cancer patients with and without co-existing diabetes, and to explore the contribution of diabetes to breast cancer survival differences between African Americans and Caucasians.

METHODS: We analyzed data from the Chicago Multiethnic Epidemiologic Breast Cancer Cohort (ChiMEC) comprising of 3170 histologically confirmed breast cancer patients diagnosed between 2004 and 2017. The cohort consists of 55% Caucasians, 38% African Americans, and 7% other ethnicities. Cox models were used to analyze data on several clinical outcomes.

Table 1 Unadjusted HR (95% CI)pAdjusted HR (95% CI)*pAll-cause mortality2.20 (1.65-2.92)<0.0011.79 (1.33-2.43<0.001Breast Cancer-specific mortality1.61 (1.06-2.44)0.0251.97 (1.27-3.05)0.002Non-breast cancer mortality3.14 (2.11-4.69)<0.0011.62 (1.06-2.47)0.025Time to recurrence1.18 (0.76-1.85)0.461.41 (0.89-2.25)0.15Recurrence-free survival1.73 (1.32-2.26)<0.0011.68 (1.27-2.22)<0.001*Adjusted for age, race, stage, hormone therapy, and chemotherapy

RESULTS: 245 patients (8%) in the cohort had co-existing diabetes at time of breast cancer diagnosis, with African Americans having highest prevalence (14%). Patients with diabetes were older (mean 66 vs. 56 years old) and had higher proportion of obesity (67% vs. 34%) and Charlson comorbidity index >2 (27% vs. 10%) than those without diabetes. The two groups were similar in terms of surgery, radiation, and hormonal therapy received, while patients with diabetes had slightly more advanced stage (15% vs. 10%). After adjusting for multiple prognostic factors, patients with diabetes had a 97% higher risk of dying from breast cancer and a 62% fold higher risk dying from other causes than patients without diabetes (Table). The two groups had no significant difference in risk of recurrence. In addition, the hazard ratio (HR) comparing African Americans with Caucasians was 2.35 (95% confidence interval [CI] 1.90-2.91), and it changed to 2.19 (95% CI 1.76-2.33) after the adjustment for diabetes.

CONCLUSIONS: Pre-existing diabetes among breast cancer patients was associated with higher risk of breast cancer specific and all-cause mortality. About 11% of racial disparities in breast cancer mortality could be attributed to higher difference in diabetes prevalence in African American patients. Further research investigating how pre-existing diabetes may influence breast cancer treatment and survival are warranted.

Citation Format: Neerukonda AR, Olopade OI, Huang E, Huo D. Type 2 diabetes and survival outcomes among a multi-ethnic cohort of breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-08-05.

Abstract P5-19-04: Psychosocial impact of a multi-modality surveillance program for women at high-risk for breast cancer

Purpose: To evaluate the psychosocial impact of semi-annual dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) screening in women at high-risk for breast cancer.

Background: For women with BRCA1 and BRCA2 mutations and/or a personal or family history of breast cancer, annual breast MRI has shown improved sensitivity and cancer detection compared to mammography. However, MRI's heightened sensitivity may lead to increased: false positives requiring additional follow-up biopsy/imaging; iatrogenic risk; and psychosocial distress, which all may negatively impact women's overall health-related quality of life.

Methods: Between 2004 and 2016, we assembled a prospective cohort of high-risk women undergoing semi-annual DCE-MRI and annual mammography. We reviewed a subset of this group. Participants completed psychosocial assessments at baseline and 6-month visits using the following measures: coping (MBSS); state/trait anxiety (STAI-S/T); depression (BDI-II); risk perception; and mental health (SF-36). Participants were classified according to Monitor or Blunter coping style. Mixed-effects logistic regressions models examined effects of demographics on psychosocial changes over time.

Results: 295 women were recruited to the study; 44% of the study participants had pathogenic mutations in BRCA1 or BRCA2 genes. 232 of 295 enrolled participants (78.6%) completed psychosocial assessments. For the total population: median age 44y (range: 21-73), 71% ≥college/post-graduate education; 84% Caucasian; 8% African American; 2% Latino; 99% with health insurance; 72% annual income of >$60,000. One third of women had a personal cancer history. Participants were evenly split between baseline Monitoring and Blunting coping style (49% and 51%, respectively). No significant differences were found between demographics (age, race, income, mutation, cancer type, cancer history) or psychosocial factors (baseline trait anxiety (p =0.64), depression (p =0.65), SF36 global health (p=0.66). After adjusting for education, race, cancer history and coping, women with ≥$60,000 income had lower trait anxiety (p<0.000) and greater mental health (p<0.001) than those with <$60,000 income. Over time, change in trait anxiety varied by coping (p=0.0006): Blunters did not experience significant changes in trait anxiety (p=0.072) while Monitors had significant diminished trait anxiety over time (p<0.001). For depression, women with ≥$60,000 income and college educated had lower BDI-II depression (p<0.000). Yet, women with a cancer history had significantly greater BDH-II depression (p= 0.048). Mental health over time varied by race as non-whites had greater gains in mental health (p=0.001) over time than whites (p=0.03).

Conclusion: Semi-annual DCE-MRI did not cause a significantly elevated state anxiety or depression, nor was there a significant decline in mental health over time for groups regardless of cancer history and genetic mutation status. Coping style may have an impact on psychosocial outcomes for those undergoing heightened surveillance over time.

Citation Format: Amico AL, Fang R, Raoul A, Wroblewski K, Nielsen S, Weipert C, Abe H, Sheth D, Romero I, Kulkarni K, Schacht D, Patrick-Miller L, Verp M, Bradbury AR, Hlubocky F, Olopade OI. Psychosocial impact of a multi-modality surveillance program for women at high-risk for breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-19-04.

Abstract P4-02-01: Recall rates during breast cancer surveillance in high-risk women with dynamic contrast-enhanced magnetic resonance imaging every 6 months: Results from a single institution study

Purpose: To compare recall rates and biopsy rates in high-risk women undergoing semi-annual dynamic contrast-enhanced magnetic resonance imaging compared to recommended annual DCE-MRI.

Background: In high-risk women with BRCA1/BRCA2 mutations and/or a personal or family history of breast cancer, annual breast MRI has shown improved sensitivity and cancer detection compared to mammography and is recommended annually in addition to mammogram. The routine use of breast MRI screening in this patient population is not widespread due to concerns for higher recall rates and false positive biopsy results, which often contribute to higher healthcare costs and increased stress. Breast MRI screening acceptability is dependent on sensitivity and recall rates. The acceptable recall rate for breast MRI is generally considered to be between 6-12% based off the results from studies that used annual DCE-MRI screening.

Methods: Between 2004 and 2016, a prospective cohort of high-risk women underwent semi-annual DCE-MRI and annual mammography. For subjects with BI-RADS score of 4 or 5 on DCE-MRI, biopsy was recommended. For subjects with BI-RADS score of 0 on DCE-MRI and/or BI-RADS scores of 0,4, or 5 on MG, further investigation by imaging was recommended and biopsy was performed if clinically appropriate. Tests with BI-RADS scores of 3 were discussed case-by-case. Recall was defined as women being recommended for further imaging (i.e. US and/or MG) in order to provide additional information. Women that are recalled may go on to have a subsequent biopsy based on the findings.

Results: 295 women were recruited to the study; 44% of the study participants had mutations in BRCA1 or BRCA2. 2111 DCE-MRI screening tests and 1225 mammography were performed. The sensitivity and specificity was 93.7% and 96.6% respectively for DCE-MRI and 50% and 97.7% respectively for mammogram. The positive predictive value was 17% for MRI and 22% for mammography. Eighty-nine women had 106 recalls. 74 due to DCE-MRI imaging alone, 18 due to mammography alone, and 14 due to both image modalities. The recall rate was 4.2% for DCE-MRI and 2.6% for mammography. In total, 56 biopsies were performed. 3 DCIS and 13 invasive breast cancers were diagnosed. On average, 5.9 women would have to be recalled on DCE-MRI with 3.3 biopsies to diagnose one cancer case. 4 women would have to be recalled on mammography with 2.1 biopsies to diagnose one cancer.

Conclusion: Semi-annual DCE-MRI screening in high-risk women demonstrated high sensitivity without substantially increasing recall rates or biopsy rates to an unacceptable value. Our single institution DCE MRI protocol achieved recall rates lower than those considered acceptable for annual MRI or mammography. This study demonstrates that with radiology reader expertise, careful clinical decision making, and improved MRI technology, it is possible to achieve recall rates lower than those achieved with annual mammography or MRI even when DCE-MRI screening exams occur more frequently than those currently recommended by guidelines. Additional data including QOL and cost effectiveness analysis will be presented.

Citation Format: Whitaker KD, Abe H, Sheth D, Huo D, Yoshimatsu TF, Verp M, Zheng Y, Karczmar G, Guindalini R, Olopade OI. Recall rates during breast cancer surveillance in high-risk women with dynamic contrast-enhanced magnetic resonance imaging every 6 months: Results from a single institution study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-02-01.

Abstract PD8-05: Comparative analysis of the genomic landscape of breast cancers from women of African and European ancestry

Objectives: Paucity of data on populations of African Ancestry in clinical trials continues to limit our ability to design and implement innovative solutions to narrow the breast cancer survival gap amongst Africans, African Americans, and European Americans. We have developed a cross-continent research infrastructure to examine the spectrum of genomic alterations in breast tumors from West Africa and subsequently, to compare them to tumors from African American women and women of European Ancestry in The Cancer Genome Atlas (TCGA) database.

Methods: Consecutive women with breast cancer presenting for treatment at the University College Hospital, Ibadan and at Lagos State University Teaching Hospital, Lagos, Nigeria gave informed consent and were recruited to the West African Breast Cancer Study (WABCS) between 2013-2016. Tumor-normal pairs were subjected to exome and/or high-depth (90x) genome sequencing. High confidence somatic mutations (substitutions, insertions/deletions and structural variants) were obtained by using multiple variant callers. Furthermore, 1,089 exomic and 80 genomic breast tumor-normal pairs from TCGA were harmonized with WABCS samples, resulting in a cohort of 147 West Africans (147 exome; 40 genome), 154 African Americans (154 exome; 31 genome), and 776 Caucasians (776 exome; 43 genome).

Results: Across the exomes, genes commonly altered in breast cancer in TCGA are also altered in women of African ancestry, but the mutational spectrum is quite different, demonstrating overrepresentation of tumors with aggressive phenotypes. Overall, TP53 (65%), ERBB2 (27%), and GATA3 (17%) showed statistically significant higher alteration frequencies in West Africans and African Americans. In contrast, PIK3CA (24%) was less frequently mutated. Of note, GATA3 mutation was statistically significantly more frequent in Nigerians (39%) and African Americans (16.7%) compared to Caucasians (10.5%), in ER-positive cancers. Analysis on Structural Variants (SV), on the other hand, has shown that the genome-wide SV counts among three populations are comparable in ER-negative cancers, while Nigerians have significantly more SV counts compared to African Americans (P=0.0013) or European Americans (P=2.9x10-5) in ER-positive cancers. Similarly, genome-wide substitution patterns in ER+ and ER- cancers varied widely by race/ethnicity. In ER- cases, West Africans carried the highest proportion of canonical APOBEC-associated substitutions, particularly C>T transitions. Conversely, European Americans with ER+ disease showed a higher proportion of C>T than both West Africans (Welch t-test P = 0.044) and African Americans (Welch t-test P = 0.011). Mutation signature analyses highlighted multiple APOBEC signatures, with notable contribution differences across ancestry and ER status. A signature likely corresponding to DNA damage repair correlated with the proportion of genetic ancestry, being most prevalent in European Americans and least common in Nigerians, particularly in ER-negative cancers, with African Americans showing a degree of this signature's contribution in between the two populations (linear model adjusted for age, P=1.0x10-10).

Conclusions: Overall, our data suggests mutation spectra differences in across race/ethnicity and geography. Identification of molecular characteristics such as higher rates of HER2 enriched tumors and higher rates of GATA3 mutations in ER positive tumors are beginning to reveal the genomic basis of race-associated phenotypes and outcomes in breast cancer. Population differences in frequency and spectrum of mutations should now inform the design of innovative clinical trials that improve health equity and accelerate Precision Oncology care in diverse populations.

Citation Format: Olopade OI, Pitt JJ, Riester M, Odetunde A, Yoshimatsu T, Labrot E, Ademola A, Sanni A, Okedere B, Mahan S, Nwosu I, Leary R, Ajani M, Johnson RS, Sveen E, Zheng Y, Wang S, Fitzgerald DJ, Grundstad J, Tuteja J, Clayton W, Khramtsova G, Oludara M, Omodele F, Benson O, Adeoye A, Morhason-Bello O, Ogundiran T, Babalola C, Popoola A, Morrissey M, Chen L, Huo D, Falusi A, Winckler W, Obafunwa J, Papoutsakis D, Ojengbede O, White KP, Ibrahim N, Oluwasola O, Barretina J. Comparative analysis of the genomic landscape of breast cancers from women of African and European ancestry [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD8-05.

Abstract P3-07-08: Molecular subtype-specific expression of long noncoding RNA regulates proliferation of basal-like breast cancer cells

Background: Basal-like breast cancer (BLBC) disproportionally affects younger women and African American women, displaying aggressive clinical behavior with poor outcomes. BLBC is difficult to treat due to its lack of defined molecular targets, and with current treatment, patients often develop metastatic disease. A growing body of evidence points to long noncoding (lnc) RNAs as mediators of tumor progression, suggesting a new class of targets in cancer therapy. While dynamic changes in lncRNA expression are observed across many types of cancer, our understanding of their role in cancer biology is limited. The aim of this study is to identify lncRNAs differentially expressed in BLBC and to characterize the functional features of candidate lncRNA.

Methods: Breast tumors and normal breast tissues were recruited from the U of Chicago Breast Cancer Tissue Bank under IRB approved protocols. Microarray profiling was done using Human LncRNA Array v3 (Arraystar) containing 30,586 lncRNAs and 26,109 mRNAs. Non-poly(A) RNAs were included with ribo-zero RNA-seq (Illumina HiSeq 4000). Molecular subtype of breast tumors was determined by PAM50 intrinsic classifier. In addition, CpG methylation of lncRNA promoter regions was analyzed with TCGA HumanMethylation450 Array data from 588 breast tissues. We performed in vitro studies using antisense oligonucleotide (ASO) knockdown and CRISPR-on overexpression in BLBC cell lines. Phenotypic consequences of perturbations of specific lncRNA expression were assessed using proliferation, apoptosis, cell cycle and homologous recombination assays.

Results: Microarray profiling of breast tissues from 30 African American women revealed a unique lncRNA signature in basal-like tumors compared to non-basal like tumors. Hundreds of lncRNAs were specifically expressed in BLBC, with >100-fold differences in some lncRNAs compared to tumors from other subtypes or normal breast tissues. Through statistical and in silico analyses we selected lncRNAs displaying increased expression in basal-like tumors (vs non-basal tumors) and BLBC cell lines (vs non-basal cell lines) with a trend of higher expression in cells isolated from women of African ancestry for functional studies. RNA-seq of 50 additional breast tissues recapitulated the distinct lncRNA clustering within the basal-like subtype. TCGA analysis of CpG islands in several lncRNA promoter regions revealed hypo-methylation when compared to non-BLBC, signifying subtype specific epigenetic regulation. ASO knockdown of candidate lncRNAs significantly increased apoptosis and decreased proliferation while CRISPR-on overexpression decreased cell sensitivity to doxorubicin treatment. Depletion of specific lncRNAs caused an increased proportion of cells in G2 phase of the cell cycle, indicating that overexpression of particular lncRNAs may contribute to aberrant cell cycle progression. Cis and trans-regulation of gene expression by lncRNAs is currently under investigation through RNA immunoprecipitation and genome-wide gene expression profiling.

Conclusion: We propose that subtype specific lncRNAs function as onco-RNAs specific to BLBC, driving cellular proliferation and increasing resistance to DNA damaging chemotherapies through regulation of the cell cycle.

Citation Format: Boatman SM, Han Y-J, Zhang J, Zheng Y, Yeh AC, Olopade OI. Molecular subtype-specific expression of long noncoding RNA regulates proliferation of basal-like breast cancer cells [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-07-08.

Abstract P1-05-11: Comprehensive comparison of breast cancer molecular portraits by African and European ancestry in the cancer genome atlas

Background: African American breast cancer patients have worse survival rates than European American patients. Although racial differences in the distribution of breast cancer intrinsic subtype are known, it is unclear if there are other inherent genomic differences contributing to this racial outcome disparity.

Methods: We defined patient race based on genomic ancestry and compared multiple molecular features of breast cancer between 154 black and 776 white patients in The Cancer Genome Atlas (TCGA). We examined the contribution of these molecular features to survival outcomes using Cox proportional hazards models. We also estimated the heritability of breast cancer subtypes using a mixed effect model.

Results: Compared to whites, black patients had higher odds of basal-like (odds ratio=3.80, p<0.001) and HER2-enriched (odds ratio=2.22, p=0.027) breast cancers in reference to luminal A subtype. Beyond differences in relative frequency of intrinsic subtypes, black and white patients had distinct gene expression, protein expression, and somatic mutation landscapes. However, the majority of these molecular differences were eliminated after adjusting for subtype; in the subtype-adjusted models, we found 142 genes, 16 methylation probes, 4 copy number segments, 1 protein, and no somatic mutation were differentially expressed or present between black and white patients. Using the top 40 differentially expressed genes, we built a race-enriched gene signature, which had excellent capacity of distinguishing breast tumors from black versus white patients (c-index=0.852 in the validation dataset). We also estimated the heritability of breast cancer subtype (basal vs. non-basal) to be 0.436 (p=1.5x10-14) and showed that two genetic variants (rs1078806 in FGFR2, rs34084277 in BABAM1) were associated with intrinsic subtype and can partially explain racial differences in subtype frequencies.

Conclusion: On the molecular level, once intrinsic subtype frequency differences are accounted for, there are few genomic or proteomic differences observed between blacks and whites. More than 40% of breast cancer subtype frequency differences may be due to genetic ancestry. These results suggest that future studies are warranted to investigate genetic and non-genetic factors that contribute to the development and progression of breast cancer subtypes in order to reduce racial disparity.

Citation Format: Huo D, Hu H, Rhie SK, Gamazon ER, Cherniack AD, Liu J, Yoshimatsu TF, Pitt JJ, Hoadley KA, Troester M, Ru Y, Lichtenberg T, Sturtz LA, Shelley CS, Mills GB, Laird PW, Shriver CD, Perou CM, Olopade OI. Comprehensive comparison of breast cancer molecular portraits by African and European ancestry in the cancer genome atlas [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-11.

Abstract P5-09-02: Breast cancer risk prediction using a polygenic risk score in women of African ancestry: Findings from GWAS in breast cancer in the African diaspora

Background: Multiple common susceptibility loci for breast cancer (BC) have been identified/confirmed in Caucasian women. Combination of these SNPs into a polygenic risk score (PRS) could improve risk stratification and provide guidance for preventive and screening strategies. However, due to differences in allele frequencies of genetic variants, tumor characteristics between women of African and European ancestries, we sought to evaluate the association of PRS with BC in a large consortium of African women.

Methods: The GWAS in BC in the African Diaspora (ROOT consortium) included 3686 participants of African ancestry from Nigeria, USA, and Barbados (1657 cases, 2029 controls). PRS was constructed from the published odds ratios (ORs) from 90 susceptibility loci for BC. Logistic regression was used to examine its association with overall BC risk as well as associations by hormone receptor status, family history and other clinical features.

Results: One unit change in the PRS was associated with an OR of 1.13 (95% CI: 1.01-1.28, P=0.042) for overall BC risk, 1.15 (95%CI: 0.95-1.41, P=0.160) for ER+ BC risk, and 1.17 (95%CI: 0.95-1.44, P=0.133) for ER- BC risk. The ORs for developing BC by percentiles of the PRS, relative to women in the middle quintile, showed weak linear trend. The discriminative accuracy of the PRS, as measured by the C-statistic, was 0.524 (95% CI: 0.505-0.542) for overall BC, 0.511(95% CI: 0.479-0.543) for ER+ BC, and 0.513 (95% CI: 0.481-0.545) for ER- BC. There was a statistically significant interaction between PRS and age, the association between PRS and overall BC risk were stronger in two age groups (aged <40 years and ≥60 years). The PRS was also more strongly associated with PR+ (OR=1.26, 95%CI: 1.01-1.58) compared to PR- (OR=1.08, 95%CI: 0.95-1.44) BC. Association between PRS and BC were similarly non-significant across different strata of family history of BC, BMI, alcohol consumption, oral contraceptive use, menopausal, ER and HER2 status.

Table 1. Performance of the 90-SNP polygenic risk score (PRS) in the GWAS in Breast Cancer in the African DiasporaPercentile of PRS (%) OR (95%CI)  Overall BC (n=1657) vs Ctrl (n=2029)ER+ BC (n=403) vs Ctrl (n=2029)ER- BC (n=374) vs Ctrl (n=2029)<51.01 (0.73-1.41)1.32 (0.28-2.13)0.89 (0.51-1.55)5-100.83 (0.59-1.15)0.71 (0.40-1.26)0.63 (0.34-1.17)10-200.74 (0.57-0.95)0.69 (0.44-1.07)0.72 (0.46-1.12)20-400.97 (0.79-1.19)0.80 (0.56-1.14)0.98 (0.69-1.39)40-601.00 (ref)1.00(ref)1.00(ref)60-800.89 (0.73-1.10)0.94 (0.66-1.33)0.90 (0.63-1.28)80-901.14 (0.89-1.47)0.87 (0.56-1.34)0.90 (0.63-1.28)90-951.14 (0.82-1.58)1.54 (0.92-2.58)0.88 (0.48-1.61)>951.10 (0.79-1.52)1.15 (0.67-1.99)1.34 (0.79-2.25)Note: Odds ratios are for different percentiles of the PRS relative to the middle quintile (40% to 60%). Odds ratios were adjusted for study site and the first ten eigenvectors from principal components analysis.

Conclusion: BC PRS obtained from prior GWASs conducted in Caucasian women didn't provide a comparable degree of risk stratification for African Americans. Additional studies are needed to identify SNPs specific to women of African ancestry that could provide improved risk prediction. Further studies can also combine the PRS with lifestyle/environmental factors.

Citation Format: Wang S, Qian F, Zheng Y, Ogundiran T, Ojengbede O, Zheng W, Blot W, Nathanson KL, Hennis A, Nemesure B, Ambs S, Olopade OI, Huo D. Breast cancer risk prediction using a polygenic risk score in women of African ancestry: Findings from GWAS in breast cancer in the African diaspora [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-09-02.

Abstract P6-04-05: Genotype-phenotype classification of triple negative breast cancers (TNBC) in women of African descent using the PAM50 NanoString platform and genomic data

Introduction: TNBC has the highest mortality rate amongst all other breast cancer types due to its complex tumor heterogeneity and lack of well-defined molecular targets. It is known that women of African descent are two to three times more likely to develop TNBC compared to women of European ancestry, yet wide-scale genomic studies of African and African American breast tumors are limited. To elucidate genotypes and molecular subtypes associated with the most aggressive forms of breast cancer, we used the PAM50 NanoString platform to reclassify Nigerian (NG), African American (AA) and Caucasian (CA) tumors previously annotated by Immunohistochemistry (IHC), and correlated our findings to their germline genotype data obtained using high-throughput technologies.

Methods: RNAs were isolated from formalin-fixed, paraffin embedded (FFPE) tumor tissues using the High Pure Paraffin Kit (Roche) following manufacturer's protocol, and assayed on NanoString nCounter Analysis System using a custom Nano110 (PAM50 + claudin-low & VEGF signatures) probe set. Intrinsic subtyping and gene-expression data were evaluated using R statistical software. All study samples were previously annotated and subtyped by the ER/PR/HER2 IHC classifier. Genotypes were obtained from next generation sequencing or Illumina Human2.5M BeadChip platform using germline DNA from more than 2000 breast cancer cases and 2000 controls were studied.

Results: To date, Intrinsic molecular subtyping by Nano110 has been completed on 69 NG, 81 AA and 74 CA tumors. Concordance between IHC and PAM50 was 59%, which is adequate and comparable to previous studies. Basal-like subtype was overrepresented and accounted for nearly 30% of NG and AA cases, compared to 17% in CA cases. HER2-enriched subtype was overrepresented only in NG cases (9%). The proportion with Luminal A tumors were 44% NG, 56% AA and 68% CA, respectively.

Conclusions: PAM50 NanoString assay is reliable and high-throughput for molecular subtyping breast cancer using RNA extracted from FFPE tumors. Ongoing work will correlate PAM50 intrinsic subtypes to genotype data.

Citation Format: Olayiwola OA, Ogundiran TO, Hardeman A, Yoshimatsu TF, Clayton W, Adeoye A, Ademola A, Ajani MA, Khramtsova G, Grushko TA, Huo D, Zheng Y, Parker J, Perou C, Olopade OI. Genotype-phenotype classification of triple negative breast cancers (TNBC) in women of African descent using the PAM50 NanoString platform and genomic data. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-04-05.

Abstract P5-04-09: Copper chaperons as novel targets for therapy in triple-negative breast cancer (TNBC)

Background: Copper metabolism is frequently dysregulated in cancer and promotes tumorigenesis. Copper chelation was shown to delay tumor development, attenuate tumor growth, block angiogenesis and inhibit metastases in preclinical breast cancer models. Copper depletion with tetrathiomolybdate (TM) in on-going phase II study for breast cancer patients at high risk for relapse resulted in significant improvement in progression-free survival, especially in patients with TNBC. We hypothesized that targeting ATOX-1 and CCS, copper chaperons that are major regulators of copper trafficking, with novel selective inhibitor may disrupt cellular copper transport and suppress TNBC cell growth, block angiogenic activity, and enhance cytotoxicity of available chemotherapy.

Methods:We measured ATOX-1 and CCS protein expression using western blot in a panel of breast cancer cell lines including TNBC cell lines with basal-like (BL) and claudin-low (CL) subtypes. We compared potency and efficacy of ATOX-1/CCS inhibitor to induce cytotoxicity in MDA-MB231, MDA-MB436, MDA-MB468 and primary normal mammary HMECs. We evaluated ability of the inhibitor to disrupt tubulogenesis of endothelial cells. To determine if blocking copper transport can enhance sensitivity of TNBC to chemotherapy we used novel ATOX-1/CCS inhibitor in combination with Cisplatin to treat TNBC in a schedule-dependent manner.

Results: ATOX-1 protein expression was elevated in all tested TNBC cell lines compared to normal HMEC (1.7±0.2 and 2.1± 0.3 folds higher in BL and CL cells, respectively). Upregulated CCS protein expression was also observed in majority of tested cell lines compared to HMEC (2.8±0.6 and 1.2±0.1 times higher in BL and CL cells, respectively). Treatment of MDA-MB231, MDA-MB436, MDA-MB468 with the inhibitor resulted in reduced cell proliferation. IC50 doses for 72h treatment with single agent were: 0.23±0.02uM (MDA-MB468), 0.29±0.03uM (MDA-MB231) and 0.35±0.02uM (MDA-MB436). Additional cytotoxicity was observed in TNBC when ATOX-1/CCS inhibitor was applied in combination with Cisplatin. Interestingly, sequential treatment resulted in synergistic effect (CI< 1). Treatment with the inhibitor reduced growth of HMECs and HuVECs in vitro, and inhibited angiogenesis in tube formation assay with HuVECs.

Conclusions: Targeting copper trafficking by selective inhibition of chaperons ATOX-1 and CCS is promising and could potentially serve as a therapeutic approach to overcome resistance to chemotherapy in TNBC. In vivo studies investigating efficacy and biological activity of the novel compound in a xenograft model are ongoing and will help to elucidate molecular mechanisms of action, and further estimate potential clinical relevance of this approach.

Citation Format: Karginova O, Song A, Wang J, Luo C, Jiang H, He C, Olopade OI. Copper chaperons as novel targets for therapy in triple-negative breast cancer (TNBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-04-09.

Abstract P6-03-17: Genomic landscape of breast cancers from women of African ancestry across the diaspora

Objectives: Of all ethnic/racial groups, age-standardized mortality rate from breast cancer is highest for African American women in the US for reasons that remain understudied. The paucity of genomic studies of breast tumors across the African Diaspora further restricts our understanding of the biology of breast cancer in underserved populations. To gain a better understanding of the genomic landscape of breast cancer in women of African Ancestry, we have developed a cross continent translational research infrastructure to examine the spectrum of genetic alterations in breast tumors from West Africa compared to the spectrum of alterations observed in tumors from African-American and other women who are predominantly white in The Cancer Genome Atlas (TCGA) dataset.

Methods: Peripheral blood and breast cancer biopsy tissues were collected from 214 patients enrolled in the West Africa Breast Cancer Study (WABCS) at the University of Ibadan/University College Hospital (UI/UCH) and at Lagos State University Teaching Hospital (LASUTH). Blood DNA as well as breast cancer tissue DNA and RNA were extracted at the Novartis Institutes for Biomedical Research (NIBR), UI/UCH, and LASUTH using a modified protocol of PAXgene Tissue DNA and RNA extraction method. Whole-exome (WES) and transcriptome (RNA-seq) sequencing were performed on the Illumina HiSeq2000 platform at NIBR. Single Nucleotide Variants (SNVs) and insertions/deletions (indels) were called using MuTect and Pindel, while Copy Number Alterations (CNAs) were called using an in-house implementation of the ABSOLUTE method. Observed mutations were compared against those reported in the TCGA dataset. ER, PR and HER2 status were determined by immunohistochemistry (IHC) at UI/UCH, LASUTH and UChicago.

Results: WES data for 95 tumors have been analyzed thus far. Genes commonly mutated in breast cancer in TCGA are also mutated in WABCS but the mutational spectrum is vastly different. TP53 (64%), MYC (31%), and GATA3 (26%), showed significantly higher alteration frequencies in WABCS and African Americans. In contrast, PIK3CA (20%), CDH1 (2%), and MAP3K1 (2%) were less frequently mutated in women of African ancestry. In addition to the high proportion with TP53 mutations, the proportion with HER2 positive subtype of 42.1% and triple-negative subtype of 37.9% suggest that tumors with the most aggressive features are overrepresented in breast cancer patients in West Africa.

Conclusions: In the first study of its kind, high throughput genomic analysis of the largest cohort of women of African ancestry has uncovered alterations in cancer genes, some of which may be amenable to treatment with targeted therapies. Furthermore, we provide evidence that population differences in frequency and spectrum of mutations should drive the design and deployment of precision medicine initiatives. Only then can we develop innovative interventions to reduce the unacceptably high rates of mortality from breast cancer in underserved and under resourced populations.

Citation Format: Olopade OI, Odetunde A, Riester M, Yoshimatsu T, Labrot E, Ademola A, Sanni A, Okedere B, Mahan S, Nwosu I, Leary R, Ajani M, Johnson RS, Sveen E, Zheng Y, Clayton W, Khramtsova G, Oludara M, Omodele F, Benson O, Adeoye A, Morhason-Bello O, Ogundiran T, Babalola C, Popoola A, Morrissey M, Huo D, Falusi A, Winckler W, Obafunwa J, Papoutsakis D, Ojengbede O, Ibrahim N, Oluwasola O, Barretina J. Genomic landscape of breast cancers from women of African ancestry across the diaspora. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-03-17.

Abstract P5-01-04: Activation of toll-like receptor 7 (TLR7) confers protection in human breast cancer

Background: Inflammation and angiogenesis in the tumor microenvironment play a role in human breast cancer. We previously showed that tumors with high M2 macrophages and high microvessel density (MVD) have a shorter overall survival. The antitumor effect of Toll-like receptor 7 (TLR7) has been previously described whereby its activation can alter the tumor microenvironment to adopt an antitumorigenic (Th-1) immune response and inhibit angiogenesis, with a potential immune mediated benefit in breast cancer. To our knowledge, there are no studies that evaluated TLR7 and its relationship to macrophages and angiogenesis in human breast cancer.

Methods: Breast tumors were obtained from the University of Chicago Breast Cancer SPORE tissue bank under IRB approved protocols. Tissue microarrays were constructed and molecular subtype was assigned based on immunohistochemical (IHC) staining into the following groups: luminal A (ER+, PR+, HER2-), luminal B (ER+, HER2+ or ER+, PR-), HER2-like (ER-, HER2+) and basal-like (ER-, HER2-, EGFR+ and/or CK5/6+). Macrophage density was determined using double staining with CD68/CD163. Microvessel density (MVD) was measured by IHC staining using anti-CD34. Staining quantification was performed by a trained pathologist and scoring performed independently by two pathologists. Based on median distribution, we assigned M2 macrophage content and MVD into high vs. low, and the TLR7 expression into faint vs. strong. To evaluate the association between M2 macrophages and TLR7, Spearman's rho correlation coefficients were calculated. Survival analysis was done using Tarone ware statistics.

Results: After removal of duplicate cores, we had 100 tumors available for scoring. There was an equal distribution of M2 macrophage content, MVD, and TLR7 expression (p = 0.074, p = 0.908, p = 0.145 respectively). The tumor subtypes were 53.2% luminal A, 34.0% basal-like, 7.4%, luminal B, and 5.3% Her2-like. We found a significant correlation between high number of M2 macrophages and high MVD (spearman's rho correlation coefficient = 0.343, p = 0.004). There was an association between M2 macrophages and TLR7 expression (Pearson χ2 = 4.425, p = 0.025). Compared to tumors with faint TLR7 expression, those with strong TLR7 expression exhibited a longer overall survival (Tarone ware statistic 5.053, p = 0.025) and this continued to be significant when adjusted for M2 macrophage content (Tarone ware statistic = 4.049, p = 0.044) and for MVD (Tarone ware statistic = 4.042, p = 0.044). There was no statistically significant association between TLR7 expression and molecular subtypes of breast cancer.

Conclusion: Tumor associated macrophages (M2 macrophages) and angiogenesis (high MVD) are known to contribute to worse outcomes in human breast cancer. Our results suggest that activation of TLR7 can have a protective effect in human breast cancer even in tumors harboring features of more aggressive disease.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-01-04.

Abstract P3-06-13: Transient increase in breast cancer risk after a full term pregnancy among African women

Background

African women affected by breast cancer (BC) have high parity with five children or more, are relatively young at first full term pregnancy (FFTP), are diagnosed at a young age and are often premenopausal at diagnosis. While several studies have assessed the role of reproductive factors for BC risk among African women, none of them have assessed whether there is dual effect of age at full term pregnancy (FTP). In this communications, using a large dataset from an on-going hospital-based case-control study, we examine the role of age at full term pregnancy on breast cancer risk among African women.

Methods

The study includes sites in Nigeria (University College Hospital, Ibadan), Cameroon (Yaoundé General Hospital) and Uganda (Breast Clinic of Mulago Hospital of Kampala). It was initiated in 1998 in Nigeria and extended to Cameroon and Uganda in 2011. Cases were consecutive females diagnosed with invasive BC. Controls were recruited from the community or within the hospital and have never being diagnosed with any cancer. Cases and controls were aged 18 years or more and gave informed consent. Full term pregnancy was defined as a pregnancy that lasted at least 7 months and included both live birth and stillbirth. Logistic regression models were used to assess the effects of age at first and second FTP, and their interaction with current age on BC risk. Age at menarche, parity, body mass index and hormone contraception use were included in the models.

Results

The study includes 1668 cases and 2399 controls recruited between 1998 and May 2013. Mean duration of live birth was 9 months (SD±0.52) and 8.8 months (SD±0.66) for a stillbirth. Overall, the mean age at FFTP was 23 years (SD±4.91) for both cases and controls. Compared to nulliparous women, parous women who had FFTP at 20 years have increased risk (OR = 1.59, CI 95%, 1.16-2.21) to develop BC in the year following the pregnancy. Up to 5 years following the FFTP, this OR is 1.38 (CI 95%, 1.06-1.80) while it is 0.77 (CI 95%, 0.62-0.95) 25 years later. This observation was also true for parous women who have had their FFTP at 25, 30, or 35 years. Moreover, a similar pattern was observed when comparing uniparous women to women with 2 or more children.

Conclusion

Our results show a transient increase in risk of BC after a full term pregnancy which declined and became protective over time. This observation is consistent with the effect of pregnancy on BC that has been described in other populations and may partially explain the current profile of breast cancer among African women.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-06-13.

Atopy is associated with asthma in adults living in rural and urban southwestern Nigeria

RATIONALE

Factors affecting the course of asthma are not clearly understood in rural and urban communities within low-resource countries. Furthermore, the interactions between atopy, environmental exposure, and helminthic infections in modulating asthma have not been well investigated.

OBJECTIVES

To conduct a feasibility study to examine the relationship between atopy and asthma in adults at two rural Health Centers and urban university college hospital in southwestern Nigeria.

METHODS

A convenient sample of 55 consecutive patients with stable physician-diagnosed asthma and 55 age-matched nonasthmatic controls seen at the outpatient clinics in two rural Health Centers and an urban university hospital were enrolled. All subjects underwent blood test, allergy skin test, and stool examination for ova and parasites. Wilcoxon sign-rank tests were used to compare serum eosinophilia and allergy skin test between the two groups.

RESULTS

Asthmatics in both urban and rural settings had significantly more positive skin reactions to house dust mite, cockroach, mold, and mouse epithelium than nonasthmatic controls (p < .05). Mean total serum IgE was also significantly higher in asthmatics than in nonasthmatic controls (360 vs. 90 IU/L, p <.001). Stool parasitemia was infrequent in both groups and not statistically significant.

CONCLUSION

Atopy is associated with adult asthma in southwest Nigeria. Larger studies to confirm the nature of this association and to examine the role of helminthic infection and other environmental factors on the expression of asthma are needed.

SNP discovery, expression and cis-regulatory variation in the UGT2B genes

UGT2B enzymes metabolize multiple endogenous and exogenous molecules, including steroid hormones and clinical drugs. However, little is known about the inter-individual variation in gene expression and its determinants. We re-sequenced candidate regulatory regions and the partial coding regions (41.1 kb) of UGT2B genes and identified 332 genetic variants. We measured gene expression in normal breast and liver samples and observed different patterns. The expression levels varied greatly across individuals in both tissues and were significantly correlated with each other in liver. Genotyping of tagging single-nucleotide polymorphisms (SNPs) in the same samples and association tests between genotype and transcript levels identified 62 variants that were associated with at least one UGT2B mRNA levels in either tissue. Most of these cis-regulatory SNPs were not shared between tissues, suggesting that this gene family is regulated in a tissue-specific manner. Our results provide insight into studying the role of UGT2B variation in hormone-dependent cancers and drug response.

Germline mutations in CDH1 are infrequent in women with early-onset or familial lobular breast cancers

BACKGROUND

Germline mutations in CDH1 are associated with hereditary diffuse gastric cancer; lobular breast cancer also occurs excessively in families with such condition.

METHOD

To determine if CDH1 is a susceptibility gene for lobular breast cancer in women without a family history of diffuse gastric cancer, germline DNA was analysed for the presence of CDH1 mutations in 318 women with lobular breast cancer who were diagnosed before the age of 45 years or had a family history of breast cancer and were not known, or known not, to be carriers of germline mutations in BRCA1 or BRCA2. Cases were ascertained through breast cancer registries and high-risk cancer genetic clinics (Breast Cancer Family Registry, the kConFab and a consortium of breast cancer genetics clinics in the United States and Spain). Additionally, Multiplex Ligation-dependent Probe Amplification was performed for 134 cases to detect large deletions.

RESULTS

No truncating mutations and no large deletions were detected. Six non-synonymous variants were found in seven families. Four (4/318 or 1.3%) are considered to be potentially pathogenic through in vitro and in silico analysis.

CONCLUSION

Potentially pathogenic germline CDH1 mutations in women with early-onset or familial lobular breast cancer are at most infrequent.

Abstract P6-01-06: Identification of Molecular Subtypes of DCIS and Invasive Breast Cancer Using Computerized Image Analysis for Data Integration

Background: Breast cancer is a heterogeneous disease with different putative therapeutic targets based upon the particular subtype. The particular subtype can have profound implications for therapy, as in the case of basal-like carcinomas which tend to be more aggressive with less therapeutic options. Although many studies have examined the transition from Ductal Carcinoma in-situ (DCIS) to Invasive Breast Cancer (IBC), the mechanisms involving the transformation are poorly understood. DCIS cases that are more likely to progress to IBC can be treated more aggressively. This study used image analysis to examine the association between predictive molecular biomarkers between pure DCIS, DCIS associated with IBC and IBC.

Methods: With approval by the Institutional Review Board, we evaluated tissue microarrays comprising 453 tissue cores from 149 patients. Five immunohistochemical biomarkers were utilized: estrogen (ER), progesterone (PR), human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), and cytokeratin 5/6 (CK-5/6). We then employed the Automated Cellular Image Analysis (ACIS) to score the biomarker status. We compared regional scoring (rated 0, 1, 2, or 3) between an experienced pathologist's subjective assessment and an automated score derived from ACIS. An image library was generated and integrated to our Translational Data Mart (TraM: http://tram.uchicago. edu). Statistical analyses included a comparison of histological grade, race, age, tumor size, and lymph node status associated with the prevalence of subtypes between pure DCIS tumors and those that advanced to IBCs. Results: The concordance between ACIS-based and pathologist-based scoring was moderate (kappa = 0.38). There was more variability in the pathologist's scoring with a standard deviation of 1.14 as compared to 0.85 for ACIS. Subtypes associated with IBC were also present in DCIS. In the pure DCIS cases, there was a higher proportion of the luminal A subtype (74.1%, n = 54) as compared to DCIS adjacent to IBC (54.2%, n=24) or pure IBC cases (57.4%, n = 115) (p=0.05). In contrast, there was more basal-like subtypes in DCIS juxtaposed with IBC (20.8%) and IBC (27.8%) than in pure DCIS tumors (9.3%).

Discussion: Molecular subtype analysis of DCIS could be useful in predicting DCIS with high risk of progressing to invasive cancer. The resemblance between subtypes bolsters the hypothesis that IBCs and DCIS originate from the same precursor lesion. Although the automated scoring featured by ACIS would be useful in expediting readings, it must be validated by a pathologist's assessment.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-01-06.

Characterizing early contrast uptake of ductal carcinoma in situ with high temporal resolution dynamic contrast-enhanced MRI of the breast: a pilot study

Improvements in the reliable diagnosis of preinvasive ductal carcinoma in situ (DCIS) by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are needed. In this study, we present a new characterization of early contrast kinetics of DCIS using high temporal resolution (HiT) DCE-MRI and compare it with other breast lesions and normal parenchyma. Forty patients with mammographic calcifications suspicious for DCIS were selected for HiT imaging using T(1)-weighted DCE-MRI with ∼7 s temporal resolution for 90 s post-contrast injection. Pixel-based and whole-lesion kinetic curves were fit to an empirical mathematical model (EMM) and several secondary kinetic parameters derived. Using the EMM parameterized and fitted concentration time curve for subsequent analysis allowed for calculation of kinetic parameters that were less susceptible to fluctuations due to noise. The parameters' initial area under the curve (iAUC) and contrast concentration at 1 min (C(1 min)) provided the highest diagnostic accuracy in the task of distinguishing pathologically proven DCIS from normal tissue. There was a trend for DCIS lesions with solid architectural pattern to exhibit a negative slope at 1 min (i.e. increased washout rate) compared to those with a cribriform pattern (p < 0.04). This pilot study demonstrates the feasibility of quantitative analysis of early contrast kinetics at high temporal resolution and points to the potential for such an analysis to improve the characterization of DCIS.

Validation of breast cancer biomarkers between a field immunohistochemistry laboratory in Nigeria and its US-based counterpart

Abstract #4039

Introduction: The importance of hormone receptor status in assigning treatment and the potential use of HER2 targeted therapy have made it imperative for laboratories to improve detection techniques. As inter-laboratory variability in immunohistochemical (IHC) tests may also affect epidemiologic studies of breast cancer subtypes in different countries, we conducted a validation study of breast cancer biomarkers between a well-established laboratory in the US and a field laboratory at the Institute for Medical Research and Training at the University College Hospital in Ibadan Nigeria.&#x2028; Method: 232 breast tumor blocks were evaluated for ER, PR, and HER2 at both laboratories using tissue micro arrays (TMA) technique. Web-based conferences were held periodically to discuss IHC staining protocols, standardize scoring systems and to resolve discrepant cases. Pathologists used whole slide imaging for joint review and kappa statistic (κ) was used to indicate concordance between the two laboratories. Fluorescence in situ hybridization was carried out to confirm HER2 status in all cases.&#x2028; Results: Initially, concordance analysis revealed an agreement of 91% (κ=0.52) for ER, 85% (κ=0.49) for PR, and 80% (κ=0.39) for HER2 between the two labs. Antigen retrieval techniques and scoring methods were identified as important reasons for discrepancy. After quality assurance and training, the agreement improved to 92% (κ=0.53) for ER, 88% (κ=0.64) for PR, and 94% (κ=0.75) for HER2. To date, florescence in situ hybridization (FISH) has been completed for 67 cases to confirm HER2 status, out of which 16 (24%) were shown to amplify the HER2 gene, 6 out of the 12 discordant HER2 results were resolved by FISH.&#x2028; Conclusion: We found web-based conference with TMA and digital microscopy a useful and cost-effective tool for quality assurance of IHC, consultation and collaboration between distant laboratories. Quality improvement exercises in testing of tumor biomarkers will reduce misclassification in epidemiologic study of breast cancer subtypes and provide much needed capacity building in resource poor field sites.&#x2028; Acknowledgement&#x2028; This study was carried out with the support of Breast SPORE NCI P50 CA125183, Breast Cancer Research Foundation and the Lee Jeans Entertainment Industry Fund.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4039.

Fluvastatin has biologic effects on stage 0 and 1 breast cancer

Abstract #4122

Introduction: Statins are safe, reduce cardiovascular risk, and impact pathways critical to cancer progression. We and others have shown lipophilic statins cause apoptosis and growth suppression in vitro and in vivo, and though epidemiologic data are mixed, statin effect appears most evident in estrogen receptor (ER) negative or grade 3 disease. To look for a direct biologic effect of lipophilic statins, we conducted a perioperative pilot window trial in women with breast cancer (BC).&#x2028; Methods: 40 subjects with stage 0,1 BC were randomized to high dose (80mg/day) or low dose (20mg/day) fluvastatin for 3-6 weeks prior to surgery. Paired tissue (core biopsy and surgical specimen), peripheral blood and MRI were obtained. Primary endpoint was Ki-67 (proliferation) change. Secondary endpoints included cleaved caspase-3 (CC3, apoptosis), longest diameter (LD) by MRI, and C-reactive protein (CRP) change. Subgroup analyses was planned by grade (3 vs. 1,2), statin dose; and ER status. Immunohistochemistry (IHC) on paraffin tissue used standard streptavidin biotin methods. A single breast pathologist reviewed all slides; a single radiologist read all MRIs, both blinded to timepoint.&#x2028; Results: Median serum cholesterol decreased by 16% (-23% and -12% for high and low dose, respectively p=0.012), indicating drug effect and compliance. 29 patients had sufficient tumor for paired IHC, 14 and 15 were grade 3 and 1,2, and 10 and 19 were ER - and +, respectively. In grade 3 (73% of which were ER-) vs. 1,2 tumors, there was a significant decrease in Ki-67, -7.2% (interquartile range (IQR) -13.4%, 0% ) vs. -0.3% (IQR -3%, .8%), respectively, p=0.04. CC3 (apoptosis) increased, 60% vs. 13% for grade 3 vs. 1,2 tumors, respectively, p=0.015. ER- and ER+ cases had a similar reduction in Ki67 with a median drop of 2% (IQR -13.4%, 1%) and 1.2% (IQR -6.6%,0.8%), respectively, p=0.56. While CC3 was increased in ER- vs. + (55% vs. 29%), the difference was not statistically significant. There was no dose dependent effect on Ki-67or CC3.There was no evidence of Ki67 or CC3 change when all grades were analyzed together (median drop 1.2%) and no change in CRP. Of 14 subjects with paired MRIs, 4 grade 3 cases showed a significant decrease in LD, marked ductal dilatation and increased necrosis.with statin exposure.&#x2028; Conclusions: A lipophilic statin, fluvastatin, reduced cholesterol and had measurable biologic changes (reduced proliferation, size and increased apoptosis) in stage 0,1 BC after only 3-6 weeks of exposure, specifically in the grade 3 subset. Results support the study of statins for chemoprevention for women at risk for or with stage 0 grade 3 BC, where new agents are needed.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4122.

Parity and breastfeeding are protective against breast cancer in Nigerian women

As the relation between reproductive factors and breast cancer risk has not been systematically studied in indigenous women of sub-Saharan Africa, we examined this in a case–control study in Nigeria. In-person interviews were conducted using structured questionnaires to collect detailed reproductive history in 819 breast cancer cases and 569 community controls between 1998 and 2006. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI). Compared with women with menarcheal age <17 years, the adjusted OR for women with menarcheal age ⩾17 years was 0.72 (95% CI: 0.54–0.95, P=0.02). Parity was negatively associated with risk (P-trend=0.02) but age at first live birth was not significant (P=0.16). Importantly, breast cancer risk decreased by 7% for every 12 months of breastfeeding (P-trend=0.005). It is worth noting that the distribution of reproductive risk factors changed significantly from early to late birth cohorts in the direction of increasing breast cancer incidence. Our findings also highlight the heterogeneity of breast cancer aetiology across populations, and indicate the need for further studies among indigenous sub-Saharan women.

An exploratory analysis of HER-2 amplification and overexpression in advanced endometrial carcinoma: a Gynecologic Oncology Group study

OBJECTIVES

To investigate the frequency and potential prognostic or predictive value of HER-2 amplification or overexpression in advanced and recurrent endometrial cancers.

METHODS

Immunohistochemical staining (IHC; DAKO Herceptest) and fluorescence in situ hybridization (FISH; Vysis Inc. PathVysion DNA Probe Kit) were performed on specimens collected on a randomized Gynecologic Oncology Group (GOG) protocol testing the addition of paclitaxel to doxorubicin/cisplatin.

RESULTS

HER-2 overexpression (either 2+ (moderate) or 3+ (strong) immunostaining) and HER-2 gene amplification (a ratio of HER-2 copies to chromosome 17 (CEP17) copies > or = 2) were detected in 44% (104 of 234; 58 were 2+ and 46 were 3+) and 12% (21 of 182) of specimens, respectively. There was a significant increased frequency of overexpression in serous tumors vs. all others (23 of 38, 61% vs. 81 of 196, 41%, respectively, P=0.03). HER-2 amplification also appeared to be more common in serous tumors, but results were not significant (6 of 28, 21% vs. 15 of 141, 11%, P=0.12). There was a significant association between grade and HER-2 amplification among nonserous tumors, with grades 1, 2, and 3 cancers demonstrating 3%, 2%, and 21% amplification, respectively (P=0.003). Neither overexpression nor amplification predicted overall survival (OS) after adjusting for treatment and performance status.

CONCLUSIONS

HER-2 amplification was more common in high grade tumors with a trend to being more common in serous tumors. There was no clear evidence for a survival difference or a difference in benefit from the addition of paclitaxel for women with HER-2 amplified or overexpressed tumors; however, power to detect clinically meaningful differences was low.

Tobacco use among individuals presenting for cancer risk assessment

1547

Background: An important component of cancer risk assessment (CRA) is the evaluation of exposures and preventive health behaviors. Tobacco use (TU) remains a significant contributor to cancer risk and decreasing tobacco use is a major national health objective. Methods: Clinical charts were reviewed to evaluate the incidence of TU and characteristics of tobacco users (TUs) among individuals presenting to the University of Chicago Cancer Risk Clinic for cancer risk assessment (CRA). Results: Among 98 individuals (97% female) presenting for CRA from 12/05–10/06, 51% (50/98) reported no TU, 38% (37/98) reported prior TU and 11% (11/98) reported current TU. Current tobacco users included 10% (7/73) of whites and 18% (4/22) of blacks with no TU among other racial groups (0/3). 45% of TUs (5/11) had a personal history of cancer. 45% of TUs reported compliance with self-breast examination, 73% with cervical cancer screening. Among TUs over 40 years old (YO), 67% (6/9) reported a mammogram in the last year and the 2 TUs over 50 YO reported a screening colonoscopy. All TUs reported interest in tobacco cessation interventions. Conclusions: Tobacco use among individuals presenting for CRA is lower than reported general population rates of TU (23%). Despite this, a proportion of individuals presenting for CRA report current TU, despite engaging in other cancer prevention behaviors. Continued review of clinical encounters from 2004- 06 (n=425) will allow for multi-variate analysis of predictors of current TU, which will inform future research employing cancer risk assessment encounters as “teachable moments” to optimize tobacco cessation outcomes.

No significant financial relationships to disclose.

BRCA1 and BRCA2 mutation carrier predictions using the BRCAPRO model in clinic-based minority families enrolled in the Breast Cancer Family Registry (B-CFR)

21037

Background: BRCA mutation prediction models, such as BRCAPRO, are used in cancer risk clinics, but they were developed based on mutation rates and penetrance observed in individuals of Ashkenazi Jewish and European ancestry. Furthermore, in clinical counseling it is not always clear whether to test additional family members for BRCA mutations after the proband tests negative. The aim of this study is to evaluate the performance of the BRCAPRO model among clinic-based minority families and to evaluate the clinical utility of testing additional family members in high risk families. Methods: A total of 314 families with at least one member having been tested for BRCA mutations were enrolled through the B-CFR. Families of Ashkenazi Jewish ancestry were excluded. Using the BRCAPRO model with default penetrance and allele frequency for non-Ashkenazi Jewish populations, the predicted likelihood of carrying either a BRCA1 or BRCA2 mutations was generated. Sensitivity, specificity, and area under the receiver operating characteristic curves (AUC) were calculated. Results: There were 55 African American, 181 Hispanic, 42 Asian American and 36 other minority families. The AUC was 0.771 (95% confidence interval, CI: 0.720–0.816) for all minorities combined. At a predicted probability of 10%, the sensitivity for identifying mutation carriers was 65% and the specificity was 76%. The performance was marginally significantly better for Hispanic families than the other minority groups (p=0.07). In 228 families (73%), multiple individuals were tested for BRCA mutations. After taking into account the mutation status of family members, the performance of the BRCAPRO model was improved: the AUC increased to 0.862 (95% CI: 0.820–0.899) and the specificity at the 10% threshold increased to 83%, while the sensitivity remained the same. Conclusions: The data support the use of BRCAPRO in pretest prediction of BRCA1/2 mutations for minority families in high risk clinic settings. Mutation status of family members provides additional predictive value, which may help counselors decide whether to offer other family members the test when one member has already tested negative, given a positive family history of breast and ovarian cancer.

No significant financial relationships to disclose.

Relationship between BRCA1 promoter methylation and sensitivity of breast cancer cell lines to cisplatin and paclitaxel

21083

Background: While BRCA1 germline mutations are uncommon, and contribute to fewer than 5% of breast cancer cases, epigenetic alterations in BRCA1 occur more frequently. BRCA1 promoter methylation has been detected in 10–30% of breast tumors. Given the role of BRCA1 in DNA repair and cell cycle regulation, we hypothesize that cells with decreased expression of BRCA1 secondary to promoter methylation will be sensitive to DNA damaging agents and resistant to microtubule inhibitors, as has previously been shown for cells deficient in BRCA1 secondary to mutation. Methods: BRCA1 methylation was determined using methylation specific PCR (MSP) as previously described (Wei et al, Cancer Research 2005). The relative sensitivities of BRCA1 methylated, mutated and competent cells to cisplatin and paclitaxel were determined in five representative breast cancer cell lines using the AlamarBlue cytotoxicity assay. Exponentially growing cells were treated with increasing concentrations of cisplatin and paclitaxel for 96 hours. IC50 values and 95% confidence intervals (CI) were calculated from sigmoidal dose response curves fitted with SAS 9.1 Proc NLIN. Western blot analysis for BRCA1 was performed on each cell line. Results: Conclusions: Only one of the two BRCA1 methylated cell lines studied (UACC3199) was sensitive to cisplatin and resistant to paclitaxel, as hypothesized. While both cell lines are methylated, western blot analysis revealed that both express BRCA1, but to a lesser degree than unmethylated cells. BRCA1 methylation, as assessed by non-quantitative MSP, does not correlate with sensitivity to cisplatin and resistance to paclitaxel. Quantification of BRCA1 promoter methylation may better predict chemosensitivity. Identification of the degree of BRCA1 methylation which does correlates with sensitivity to cisplatin and resistance to paclitaxel could improve treatment selection for patients with breast cancer. This work was supported by the US Army Grant W81XWH-04–1-0545.

[Table: see text]

No significant financial relationships to disclose.

Health-related quality of life among high-risk women in an MRI surveillance study

1522

Background: The quality of life (QOL) and psychological impact of incorporating MRI into breast cancer screening programs for high-risk women (HRW) has not been well studied. Psychological and biological risk factors, e.g. cancer history, BRCA mutation, imaging recall, generalized anxiety or clinical depression may mediate QOL outcomes. Methods: 100 HRW undergoing intensive surveillance including yearly mammography, semiannual breast ultrasound and breast MRI have completed QOL (SF-36), anxiety (STAI) and depression (Beck) questionnaires at semi-annual visits. 56 HRW have completed 3 screenings. Differences in QOL measures over time were evaluated using longitudinal regression models. Differences between participants and population norms (PN), women with/without a history of cancer and with/without a BRCA mutation were assessed using t-tests. Results: QOL scores increased over time and were statistically significant for the general health (GH) subscale (p=0.016). All QOL subscales were higher than PN at baseline and were significantly higher than PN at 12 months. Mean GH score at 12 months = 80.0, PN 72.7 (SD14.2, p<0.01). Mean mental health score at 12 months = 78.9, PN 73.4 (SD14.9, p<0.01). At baseline, BRCA carriers had lower QOL scores than non-carriers and women with a history of cancer had higher QOL scores than unaffected participants, although these differences were not statistically significant. Conclusions: These data suggest that intensive breast cancer screening incorporating breast MRI may have a positive effect among HRW. Continued enrollment will allow for multi-variate characterization of psychological and biological predictors of change in QOL and psychological well-being among high-risk women undergoing intensive screening.

No significant financial relationships to disclose.

Content and method of parental disclosure of genetic risk to young adult and minor children in BRCA families

1536

Background: Prior research has found that many BRCA mutation carriers report discussing their genetic test results with their minor children. The content, method and process of this communication have not been previously described. Methods: 20 parents (yielding 42 parent-offspring pairs, POP) have completed a 62-item questionnaire regarding the content and methods of communication of genetic risk to offspring. Results: Of 19 (45%) POP where parents reported disclosure of their BRCA mutation to offspring in response to a binary (yes/no) question, all reported telling their children about the genetic mutation itself, as well as the parents’ risk for cancer. In 74% of POP the offspring’s chance of inheriting the mutation or risk for cancer were said to have been communicated. In 53% of POP parents reported discussion of parental risk reduction measures, and in only 37% of POP parents reported communication of offspring risk reduction measures. Of the POP where parents reported some communication of cancer risk, 22% described incorporating written materials. In 75% of POP parents reported communication through multiple conversations over time (1 -20 conversations, up to 4 years). Conclusions: Although many BRCA carriers report discussing their genetic mutation with offspring, the content and extent of parental communication is variable, often including information regarding the genetic mutation, but less frequently the offspring’s risk of inheriting the gene and infrequently communication regarding risk reduction measures. Further research on this expanding cohort will allow for analyses of parent and child factors associated with disclosure content in order to guide the development of interventions to facilitate age and content-appropriate communication of genetic risk to at-risk offspring.

No significant financial relationships to disclose.

Outcomes after breast cancer in an ethnically diverse cohort of high-risk patients: Differences in survival based on BRCA1/BRCA2 mutation status

21116

Background: Most studies of hereditary breast cancer report that BRCA1 associated tumors are characterized by high grade and hormone receptor negativity, while those associated with BRCA2 are more similar to sporadic cases. Several groups have demonstrated that BRCA1 mutations, but not BRCA2 mutations, are associated with reduced survival in women with breast cancer. These studies have primarily included women of European and Ashkenazi Jewish heritage. No study to date has assessed outcomes in an ethnically diverse cohort of high-risk individuals. Methods: High-risk individuals were identified through the University of Chicago Cancer Risk Clinic (UCCRC). Clinicopathologic data was collected on all patients with breast cancer who had undergone genetic testing and consented to inclusion in research protocols. Recurrence-free survival (RFS) and overall survival (OS) for BRCA1, BRCA2 and non-carriers was compared using the log-rank test. Hazard ratios (HR) and 95% Confidence Intervals (95% CI) were calculated from Cox proportional hazard models. Results: 280 patients from 258 families were studied. 67 were BRCA1 mutation positive, 36 were BRCA2 positive and 177 were non-carriers. 65% of patients were non-Hispanic non-Jewish whites, 15% African American, 15% Ashkanazi Jewish, 3% Hispanic and 2% Asian. At a median follow up of 5 years, 40 patients had relapsed and 22 had died. HRs (95% CI) for RFS of the BRCA1 and BRCA2 carriers relative to non-carriers were 1.6 (0.77–3.33) and 1.3 (0.55–3.09) respectively, when adjusted for year at diagnosis. The adjusted HRs (95% CI) for OS for the BRCA1 and BRCA2 carriers relative to non-carriers were 1.82 (0.48–3.02) and 0.67 (0.15–3.04), respectively. Conclusions: In this study of an ethnically diverse cohort of high-risk individuals, BRCA1 mutation carriers had a poorer outcome as compared to those with BRCA2 mutations or those without identifiable mutations in either gene, although this difference was not statistically significant. This observation is consistent with previous studies of women of predominantly Ashkenzi Jewish and European ancestry. This study was funded by the Falk Medical Research Trust, the Breast Cancer Research Foundation and the Entertainment Industry Fund.

No significant financial relationships to disclose.

Disclosure patterns and decision making preferences in BRCA 1/2 mutation carriers with young adult and minor children

1015

Background: Genetic testing of minors for adult-onset diseases has generally been discouraged. Yet, limited data suggests that many BRCA mutation carriers discuss their test results with their minor children. How parents make the decision to share this information and the effects on their health, their child and the family remains unknown. Methods: We sought to evaluate disclosure patterns and decision making practices among BRCA1/2 mutation carriers with children under the age of 25. 42 parents (with 86 children) completed a semi-structured telephone interview regarding communication of their genetic test results to their children. Chi-squared tests to assess associations between parent/child characteristics and disclosure were computed using robust variance estimates to account for clustering by family unit. Results: 55% of parents discussed hereditary risk of cancer and/or their genetic test results with at least one child. Factors associated with disclosure included older child age (p<0.001), female parent gender (p=0.049), parent history of prophylactic surgery (mastectomy: p = 0.021, oophorectomy: p<0.001) and education limited to high school (p=0.085). Child gender and parent’s history of cancer were not significantly associated with disclosure. Most participants reported themselves (45%) or their spouse (40%) as the most important person in the decision to disclose. Reports of physician (14%) and genetic counselor (21%) involvement were low. Conclusions: Parental decisions to disclose BRCA test results to children are complex and may reflect differences in perceptions of genetic disease. Further research is needed to understand parental motivations for disclosure and to define a role for health care professionals to improve counseling and recommendations regarding the risks and benefits of early communication of genetic risk to children.

No significant financial relationships to disclose.

Phenotypic heterogeneity in multiple myeloma families

PURPOSE

To describe a series of families with familial multiple myeloma (MM). Observations were used to generate hypotheses about the role of genetic factors, the mode of inheritance of these factors, and the association of other cancers with familial MM.

PATIENTS AND METHODS

This observational study consisted of 39 families with multiple cases of MM or related disorders from four collaborating research centers. Each center followed its usual family study method. Probands were interviewed, and, when possible, cancers were verified by medical records and pathology review. A working pedigree was compiled on each family.

RESULTS

Seventeen families had affected members in two or more generations, and eight families had two or more affected members in a single generation. Four families had two or more members with plasma cell dyscrasias, with or without a single case of MM. In the remaining 10 families, a single MM case occurred with a family history of other cancers. Other cancers observed in family members included hematologic malignancies and solid tumors. In families with MM in multiple generations, there was a decrease in the age at MM diagnosis in successive generations.

CONCLUSION

The study of familial MM may provide insights into the pathogenesis and, ultimately, the control and prevention of MM and related disorders. Population-based epidemiologic studies are crucial, but because of the rarity of familial MM, a concerted case-finding approach may also be fruitful. Therefore, we propose an international consortium to study familial MM, and we invite all interested colleagues to participate.