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In experimental and clinical studies, green or black tea consumption has been shown to reduce oxidative stress. However, these studies involved high levels of tea consumption and may not reflect patterns in the general population. Here, we examined the association between black or green tea consumption and oxidative stress in a cross-sectional study of 889 premenopausal US women aged 35–54 years. Tea consumption was measured using the Block-98 FFQ. Urinary 8-iso-PGF2α (F2-IsoP) and 2,3-dinor-5,6-dihydro-15-F2t-isoprostane (15-F2t-IsoP-M) were used as biomarkers of oxidative stress. These compounds were measured by MS and normalised to creatinine. Linear regression was used to calculate the geometric mean differences (GMD) and 95% CI for log-transformed urinary F2-IsoP or 15-F2t-IsoP-M in relation to black or green tea consumption. We further examined whether adjusting for caffeine impacted associations between tea and oxidative stress. Geometric means of urinary F2-IsoP and 15-F2t-IsoP-M were 1·44 (95% CI 1·39, 1·49) and 0·71 (95% CI 0·69, 0·73) ng/mg creatinine, respectively. Overall, green tea consumption was not associated with urinary F2-IsoP or 15-F2t-IsoP-M. High-level black tea consumption (≥5 cups/week compared with 0) was associated with higher 15-F2t-IsoP-M concentrations (adjusted GMD=0·10, 95 % CI 0·02–0.19) but not F2-IsoP. Adjusting for caffeine nullified the association between black tea and 15-F2t-IsoP-M. Our findings do not support the hypothesis that dietary tea consumption is inversely associated with oxidative stress.

594 Background: Black women with breast cancer have higher mortality than White women. Differences in tumor biology contribute to racial disparities in breast cancer outcomes. BIRC5 gene encodes survivin, an inhibitor of apoptosis protein, and an independent marker of poor prognosis in breast cancer. Cancer patients have anti-survivin antibodies and circulating survivin-specific T cells, suggesting that survivin may be targetable. Several ongoing antibody-mediated, vaccine strategies that target survivin are being developed. Nevertheless, most survivin studies were conducted in cohorts of White women. To date, the prevalence and/or role of survivin expression in breast tumors from Black women has not been studied. Methods: Associations between BIRC5 expression, clinicopathological and molecular features were measured in the population-based Carolina Breast Cancer Study (CBCS) and The Cancer Genome Atlas (TCGA) breast cancer cohort. Gene expression was measured by Nanostring RNA counting and split into BIRC5 high (4th quartile) and low categories based on log2 gene expression values. Relative frequency differences (RFD) for the association between BIRC5 high and clinicopathologic features were estimated. RNA based p53 mutant status and homologous recombination deficiency (HRD) status were included in RFD analysis. Receiver operating characteristic (ROC) curves were used to illustrate the potential of BIRC5 expression to distinguish patients who achieved pathological complete response (pCR) after receiving neoadjuvant chemotherapy in CBCS (133 Black, 49 non-Black). Results: BIRC5 gene expression was significantly increased in tumors from 966 Black patients compared to 1,497 non-Black (p < 0.00001), adjusting for stage and subtype. BIRC5 high tumors were significantly more expressed in higher stage and basal-like breast cancer subtypes. BIRC5 high tumors were also significantly enriched for expression of genes involved in p53 loss and HRD. Furthermore, in an analysis of 182 CBCS patients, BIRC5 gene expression alone predicted pCR with similar overall AUC to ROR-PT multigene signatures (AUC 0.62 vs 0.64). Conclusions: Our study shows that survivin expression is particularly high in breast tumors from Black women. This was associated with more aggressive clinicopathological features in addition to p53 mutant and HRD status. Black women with breast cancer represent an area of unmet clinical need and could potentially benefit from anti-survivin targetable treatment strategies. Further studies are needed to help close this gap which constitutes the largest disparity among cancer-specific diseases.[Table: see text]

TPS10609 Background: ECOG-ACRIN launched the Tomosynthesis Mammographic Imaging Screening Trial (TMIST) through the National Cancer Institute’s National Clinical Trials Network (NCTN)— a network of academic medical centers, community hospitals, and private clinical practices that are committed to participating in NCI-funded clinical trials. The NCI NCTN was developed to support rapid trial start-up of NCI-funded cancer control/prevention, cancer treatment, and non-therapeutic clinical trials that occur within the institution through centralized institutional administration and shared clinical resource allocation (personnel, lab services). TMIST is a randomized clinical trial assessing two breast cancer screening imaging modalities, tomosynthesis and digital mammography, in the population of women presenting for screening mammography and therefore requires active involvement of radiology. Methods: TMIST seeks to enroll 164,946 women, ages 45 to 74 years who present for screening mammography. Because the population under evaluation are women already scheduled for screening mammography, the mammography clinic is critical to successful recruitment as well as adherence to imaging randomization assignments over a 5-year period and therefore must be actively engaged in this trial with a breast imaging radiologist championing the trial within this service. To get active engagement of breast imaging radiologists, we needed to first make them aware of TMIST. Breast imaging radiologists that were already actively involved in the NCTN received notification of the trial through the NCTN email lists. So our goal was to come up with a strategy to reach out to breast imaging radiologists that were not active members in the NCTN. This was achieved through in-person informational sessions to introduce the trial at national and international breast imaging meetings, introduction of the trial and the workings of the NCTN network to the radiology community through articles placed in American College of Radiology (ACR) newsletters, ads promoting TMIST on ACR social media platforms, and direct email by the TMIST study chair to key radiology stakeholders. As of February 15, 2021, there are 115 sites open: 106 in the U.S. and 9 internationally with an additional 54 sites planning to open. A total of 39,366 women are enrolled in the trial with two-thirds also consenting to optional blood and/or buccal cell collection. Minority populations’ participation in the trial is over 20%. A significant drop in enrollment occurred in Spring 2020 coinciding with the suspension of mammography services globally due to COVID-19 beginning mid-March 2020. Enrollment and follow-up screening visits for TMIST restarted in May 2020 and gradually ramped back up to pre-COVID totals in September 2020. Our highest monthly accrual so far occurred in November 2020 with 2,148 subjects enrolled. Clinical trial information: NCT03233191 .

Background: Black breast cancer patients have p53 loss in 60% of their tumors, compared to 35% p53 loss in white breast cancer patients. The tumor suppressor p53 has pleiotropic effects on DNA repair, as it regulates both error prone and error-free DNA repair pathways. These effects on DNA repair represent molecular vulnerabilities that influence chemotherapy response, both directly and indirectly through the activation of immune responses. While studies have begun to elucidate DNA repair imbalance and immune response in human cancer, little is known about how these pathways differ by race. Methods: To study DNA repair and immune response in breast cancer, we performed gene expression analysis on FFPE samples from the Carolina Breast Cancer Study (CBCS), a large population-based study that oversampled black and younger women. We curated a list of DNA repair genes representing regulators of error prone and error free DNA repair. Pathways included Nucleotide Excision Repair (NER), Fanconi Anemia (FA), Mismatch repair (MMR), Base Excision Repair (BER), Homologous Recombination (HR), Translesion Synthesis (TLS), Alternative End Joining (AEJ), Checkpoint, and APOBEC. In addition, we developed a 50-gene immune panel representing 12 individual immune cell types (B cells, T cells, Treg cells, T help cells, T follicular helper cells, CD8 T cells, NK cells, Eosinophils, Neutrophils, M1 & M2 Macrophages) and both adaptive and innate arms of the immune system. A total of 1464 patients (53% black, 53% under 50) were included in the current analysis. We used consensus clustering to identify groups of patients based on DNA repair gene expression and used linear regression to estimate the relative frequency differences between these classes and demographic and clinical characteristics. Results: We found that breast cancers grouped into four clusters based on DNA repair gene expression. One cluster, ‘Repair High’, represented 32% of the tumors, and had high expression of NER, NHEJ, HR, and FA genes, suggesting a broad DNA repair response. Another group, ‘HR/FA High’ represented 23% of the tumors and was enriched for high expression of HR and FA genes. An “APOBEC High” group consisted of 32% of the tumors and was enriched for high expression of APOBEC family genes (APOBEC3D, APOBEC1, APOBEC3A, APOBEC3H, APOBEC3B). Finally, 13% of tumors, had a ‘Heterogeneous Repair’ pattern of high expression of HR, NHEJ, and FA genes, but lower expression of NER genes. The HR/FA and Heterogeneous Repair groups were enriched for TP53 mutant-like tumors (93% vs. 5% and 61% vs. 38% Mutant vs. Wildtype respectively). In addition, the Heterogeneous Repair group was enriched for Hormone Receptor positive samples ([RFD] 8.2% (0.613, 15.3), 77% vs. 23% in positive vs. negative respectively), while the HR/FA High group was significantly enriched for TNBC ([RFD] HR/FA: 51.2% (45.1, 57.1), 75% vs. 25% TNBC vs. non-TNBC respectively). The Repair High group was the only group enriched for non-black race ([RFD]: 10.4% (4.0, 16.7), 42% vs. 58% in blacks vs. non-blacks respectively). Finally, DNA repair classes were associated with immune scores, with the APOBEC High tumors having a significantly higher Eosinophil score (p = 0.021) and Neutrophil score (p = 0.007) compared to the other four groups. Conclusion: DNA repair expression is highly variable across breast tumors and may depend upon TP53 status, tumor subtype, and race. Differential immune marker expression by DNA repair group suggests some DNA repair groups may have differential response to immune-targeted therapies. DNA repair, immune response, and race are inter-related in breast cancer and unraveling and ultimately targeting breast cancer disparities may require coordinated evaluation of these pathways. Citation Format: Andrea Walens, Alina M Hamilton, Markia A Smith, Xiaohua Gao, Erin L Kirk, Stephen D Hursting, Katherine A Hoadley, Cyrus Vaziri, Melissa A Troester. Dna repair imbalance and immune response in breast cancer mortality disparities [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS19-03.

// Yirong Zhu 1 , Mark D. Aupperlee 2 , Yong Zhao 2 , Ying Siow Tan 2 , Erin L. Kirk 4 , Xuezheng Sun 4 , Melissa A. Troester 4, 5, 6 , Richard C. Schwartz 3 , Sandra Z. Haslam 2 1 Cell and Molecular Biology Program and Breast Cancer and the Environment Research Program, Michigan State University, East Lansing, MI, USA 2 Department of Physiology and Breast Cancer and the Environment Research Program, Michigan State University, East Lansing, MI, USA 3 Department of Microbiology and Molecular Genetics and Breast Cancer and the Environment Research Program, Michigan State University, East Lansing, MI, USA 4 Department of Epidemiology, University of North Carolina at Chapel Hill, NC, USA 5 Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, NC, USA 6 Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, NC, USA Correspondence to: Sandra Z. Haslam, email: shaslam@msu.edu Richard C. Schwartz, email: schwart9@msu.edu Keywords: dietary animal fat, breast cancer, puberty, adulthood, Trp53-null Received: July 22, 2016 Accepted: October 19, 2016 Published: November 04, 2016 ABSTRACT Premenopausal breast cancer is associated with increased animal fat consumption among normal weight, but not overweight women (Farvid et al., 2014). Our previous findings in obesity-resistant BALB/c mice similarly showed promotion of carcinogen-induced mammary tumorigenesis by a diet high in saturated animal fat (HFD). This effect was specific to pubertal versus adult HFD. This study identifies the effects of HFD during puberty versus adulthood in Trp53-null transplant BALB/c mice and investigates its mechanism of enhancing tumorigenesis. Either pubertal or adult HFD is sufficient to increase incidence of Trp53-null mammary tumors. Puberty-restricted HFD exposure promoted tumor cell proliferation, increased angiogenesis, and increased recruitment of total and M2 macrophages in epithelial tumors. Adult-restricted exposure to HFD similarly increased proliferation, angiogenesis, recruitment of total and M2 macrophages, and additionally reduced apoptosis. Adult HFD also increased incidence of spindle cell carcinomas resembling claudin-low breast cancer, and thus adult HFD in the Trp53-null transplantation system may be a useful model for human claudin low breast cancer. Importantly, these results on Trp53-null and our prior studies on DMBA-induced mammary tumorigenesis demonstrate a pubertal window of susceptibility to the promotional effects of HFD, indicating the potential of early life dietary intervention to reduce breast cancer risk.

Colorectal cancer is the third most common cancer in men and women in the US, with over 95,000 new cases expected in 2016 (1). Many preclinical, epidemiological, and clinical studies have shown that regular aspirin (acetylsalicylic acid) use, even in low-doses, prevents the development of colorectal neoplasia (2-5). In 2015, the US Preventative Services Task Force acknowledged the value of low-dose aspirin in primary prevention of colorectal cancer in adults aged 50–59 years (6). Despite this wealth of evidence, how aspirin reduces colorectal cancer risk is not fully understood. Many mechanisms have been proposed, but the most commonly cited is aspirin’s inhibition of PTGS2 (COX-2), a known mediator of inflammation and immunosuppression that is overexpressed in many colorectal neoplasms (7-12).

There are currently no reports describing mammary gland development in the Harlan Sprague-Dawley (HSD) rat, the current strain of choice for National Toxicology Program (NTP) testing. Our goals were to empower the NTP, contract labs, and other researchers in understanding and interpreting chemical effects in this rat strain. To delineate similarities/differences between the female and male mammary gland, data were compiled starting on embryonic day 15.5 through postnatal day 70. Mammary gland whole mounts, histology sections, and immunohistochemically stained tissues for estrogen, progesterone, and androgen receptors were evaluated in both sexes; qualitative and quantitative differences are highlighted using a comprehensive visual timeline. Research on endocrine disrupting chemicals in animal models has highlighted chemically induced mammary gland anomalies that may potentially impact human health. In order to investigate these effects within the HSD strain, 2,3,7,8-tetrachlorodibenzo -p-dioxin, diethylstilbestrol, or vehicle control was gavage dosed on gestation day 15 and 18 to demonstrate delayed, accelerated, and control mammary gland growth in offspring, respectively. We provide illustrations of normal and chemically altered mammary gland development in HSD male and female rats to help inform researchers unfamiliar with the tissue and may facilitate enhanced evaluation of both male and female mammary glands in juvenile toxicity studies.

Black women experience higher rates of hysterectomy than other women in the United States. Although research indicates that premenopausal hysterectomy with bilateral oophorectomy decreases the risk of breast cancer in black women, it remains unclear how hysterectomy without ovary removal affects risk, whether menopausal hormone therapy use attenuates inverse associations, and whether associations vary by cancer subtype. In the population-based, case-control Carolina Breast Cancer Study of invasive breast cancer in 1,391 black (725 cases, 666 controls) and 1,727 white (939 cases, 788 controls) women in North Carolina (1993–2001), we investigated the associations of premenopausal hysterectomy and oophorectomy with breast cancer risk. Compared with no history of premenopausal surgery, bilateral oophorectomy and hysterectomy without oophorectomy were associated with lower odds of breast cancer (for bilateral oophorectomy, multivariable-adjusted odds ratios = 0.60, 95% confidence interval: 0.47, 0.77; for hysterectomy without oophorectomy, multivariable-adjusted odds ratios = 0.68, 95% confidence interval: 0.55, 0.84). Estimates did not vary by race and were similar for hormone receptor–positive and hormone receptor–negative cancers. Use of estrogen-only menopausal hormone therapy did not attenuate the associations. Premenopausal hysterectomy, even without ovary removal, may reduce the long-term risk of hormone receptor–positive and hormone receptor–negative breast cancers. Varying rates of hysterectomy are a potentially important contributor to differences in breast cancer incidence among racial/ethnic groups.

Introduction: The clinical classification of breast cancer into at least four intrinsic subtypes has advanced targeted therapy and improved prognosis. However, for etiological classification, it has been proposed that breast cancer is comprised of just two main subtypes: basal-like and non-basal-like. Evidence for these two etiologic subtypes emerges strongly from bimodal age frequency distributions at diagnosis. In the absence of RNA-based intrinsic subtyping, estrogen receptor (ER) expression is a useful surrogate for these two distinct etiologic classes. Using data from the population-based Carolina Breast Cancer Study (CBCS), we examined evidence for a two-component (ER-positive vs. ER-negative) mixture model for breast cancer biologic/etiologic heterogeneity. Methods: Automated digital scoring of ER expression was performed on immunohistochemistry-stained tissue microarrays comprising 1,920 invasive breast cancer cases from CBCS. Clinical classification of ER status has changed over time as new data have emerged regarding optimal treatment-relevant thresholds, but optimal etiologic thresholds have not been established. Therefore, we considered ER status as a quantitative, categorical variable with cut points of Results: As expected for etiologically-distinct entities, ER-negative and highly ER-positive tumors showed predominantly unimodal early-onset and late-onset age distributions at diagnosis with peak frequencies near ages 50 and 70 years, respectively. However, tumors with low and intermediate positivity showed bimodal patterns, consistent with a mixture of two main subtypes. Consistent with these age distribution patterns, young age ( Conclusions: While etiologic differences between dichotomized ER-negative and ER-positive breast cancer categories have been well described in many epidemiologic studies, differences in breast cancer etiology across quantitative levels of ER expression have not been so well-characterized. In this study, we report that ER-positive tumors with low positivity share etiologic features of ER-negative tumors, including young age at diagnosis and aggressive tumor characteristics. These data provide additional support for a two-component breast cancer mixture model, with quantitative level of ER positivity reflecting the relative distributions of ER-positive and ER-negative tumor populations. Citation Format: Allott EH, Tse C-K, Carey L, Anderson WF, Olshan AF, Troester MA. Etiologic heterogeneity in breast cancer across quantitative levels of estrogen receptor expression. [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 P1-07-04.

Purpose Oncotype DX (ODX) is a tumor gene-profiling test that aids in adjuvant chemotherapy decision-making. ODX has the potential to improve quality of care; however, if not equally accessible across racial groups, disparities in cancer care quality may persist or worsen. We examined racial disparities in ODX testing uptake. Methods We used data from the Carolina Breast Cancer Study, phase III, a longitudinal, population-based study of 2,998 North Carolina women who received a diagnosis of breast cancer between 2008 and 2014. Our primary analysis used modified Poisson regression to determine the association between race and whether ODX testing was ordered among two strata: node-negative and node-positive breast cancer. Results A total of 1,468 women with estrogen receptor–positive, human epidermal growth factor receptor-2–negative, stage I or II breast cancer met inclusion criteria. Black patients had higher-grade and larger tumors, more comorbidities, younger age at diagnosis, and lower socioeconomic status than non-black women. Overall, 42% of women had ODX test results in their pathology reports. Compared with those who did not receive ODX testing, women who received ODX testing tended to be younger and have medium tumor size and grade. Our regression analyses indicated no racial disparities in ODX uptake among node-negative patients. However, racial differences were detected among node-positive patients, with black patients being 46% less likely to receive ODX testing than non-black women (adjusted relative risk, 0.54; 95% CI, 0.35 to 0.84; P = .006). Conclusion We did not find racial disparities in ODX testing for node-negative patients for whom ODX testing is guideline recommended and widely covered by insurers. However, our findings suggest that a newer, non–guideline-concordant application of ODX testing for node-positive breast cancer was accessed less by black women than by non-black women, reflecting more guideline concordant care among black women.

Background: Black women have disproportionately higher incidences of Basal-like breast cancer; prior work in the Carolina Breast Cancer Study (CBCS) has also identified higher ROR in Black women among clinically-defined hormone receptor (HR) positive, HER2 negative patients. Tumor expression-based scores of risk of recurrence (ROR) are vital prognostic tools. Investigation of germline genetic variation in relation to ROR by race strata (White, Black) may offer insight into racially divergent ROR patterns. Methods: From a panel of 417 breast-cancer related genes, we identified 46 genes (Black) and 57 genes (White) with significant cis- heritability and high cross-validation prediction performance in race-specific predictive models of tumor expression from germline genotype. We performed race- specific (N=1,043 White, N=1,083 Black) multivariable linear regression of imputed germline genotype-regulated tumor gene expression (GReX) against ROR scores (ROR-S, Proliferation, ROR-P), adjusting for age, HR status, stage, and CBCS phase as well as multiple tests via the Benjamini-Hochberg procedure. We further performed permutation testing of adjusted R^2 of significant GReX genes against covariate (age, HR, stage, phase) residualized ROR scores. Lastly, we performed race-specific multinomial logistic regression for significant GReX genes against PAM50 expression based BC subtypes. Results: Among White women, GReX of MCM10, FAM64A, NDC80, CCNB2, MMP1, VAV3, PCSK6, and GNG11 was positively associated with ROR while GReX of VAV3, PCSK6, and GNG11 was negatively associated with ROR. Congruent with this observation, GReX of the higher and lower ROR gene sets were associated with significantly increased and decreased odds of Basal-like BC (ref. Luminal A), respectively (e.g. MCM10 odds ratio (OR) and 95% confidence interval (CI): 1.42 [1.18, 1.71]; VAV3 OR and 95% CI: 0.75 [0.63, 0.90]). Similar, but lesser effects were seen for the higher and lower ROR GReX sets for HER2 and Luminal B subtype (ref. Luminal A). Among Blacks, only MMP1 GReX predicted Proliferation and ROR-P, but not ROR-S. MMP1 GReX was found to lower Proliferation and ROR-P, contrary to findings among Whites. Conclusions: We show that GReX of non-PAM50 genes can predict ROR scores and that this relationship may partly be a consequence of non-PAM50 GReX influencing intrinsic BC subtype propensities. Differences in GReX-ROR relationships across race may be informative towards racial differences in ROR scores, underlying tumor molecular signature, and subsequent clinical outcomes. Citation Format: Achal Patel, Arjun Bhattacharya, Melissa Troester, Michael Love. Germline-genome regulated tumor gene expression in relation to risk of recurrence scores in White and Black breast cancer populations [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-148.

Background: Disparities in adjuvant endocrine therapy (AET) initiation and adherence have been shown by race/ethnicity, however the relationship among American Indian/Alaskan Natives (AIAN) is poorly understood, particularly among the 73% of urban residing AIAN. We evaluated whether AET-initiation and adherence were lower among AIAN than other races/ethnicities enrolled in Kaiser Permanente of Northern California (KPNC) health system. Methods: We identified 23,680 AET- eligible (first primary, stage I-III, hormone receptor-positive breast cancers) patients from 1997 to 2014 and used KPNC’s pharmacy records to identify AET-prescriptions and refill dates. We assessed AET-initiation (≥1 filled prescription within 1-year of diagnosis) and AET-adherence (proportion of days covered [PDC] ≥80%) every year up to 5-years post AET-initiation. Results: At the end of the 5-year period, 83% were AET-initiators and 58% were AET-adherent. Compared to all other races/ethnicities, AIAN women had the second lowest AET-initiation (Black=78.0%, AIAN=78.6%, Hispanic=83.0%, non-Hispanic white [NHW]=82.5%, Asian=84.7%), the lowest AET- adherence by the end of the 1-year and 5-year period (70.3% and 50.8% vs. NHW=76.4% and 58.8%, respectively), and the greatest AET-discontinuation in year period 4 to 5 (13.8% AET-adherence decrease, 64.6% to 50.8%), after AET-initiation. In the multivariable models adjusting for age, socioeconomic and clinical factors, AIAN, Hispanic, and Black women were less likely than NHW women to be AET- adherent although the number of AIAN was small leading to imprecise estimates. At the end of the 5-year period, total underutilization (combining initiation and adherence) in AET-eligible was greatest among AIAN (70.6%), followed by Black (69.6%), Hispanic (63.2%), NHW (58.7%), and Asian (52.3%), underscoring the AET- treatment gap. Conclusion: Our results suggest that AET-initiation and adherence are particularly low for insured AIAN women. Results suggest that interventions are needed, even for urban, insured AIAN women who tend to have greater geographic access and fewer financial issues than their rural counterparts. Citation Format: Marc A. Emerson, Ninah Achacoso, Halei C. Benefield, Melissa A. Troester, Laurel A. Habel. Initiation and adherence to adjuvant endocrine therapy among urban, insured American Indian/Alaskan Native breast cancer survivors [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-114.

Background Multigene assays for breast cancer are becoming more commonly used for research, diagnostic, and treatment-selection purposes. These assays are commonly based on a single tumor sample, so this study assesses whether clinically-relevant multigene scores are subject to misclassification due to technical variation or intratumoral heterogeneity. Methods Using FFPE blocks, tumors from 37 patients were sampled at different pathologist-selected spatial locations, targeting regions with distinct histological appearance. A second pathologist assessed mitotic activity and presence of immune infiltration for each specimen. Gene expression was quantified using the PAM50 assay. Samples were classified with respect to intrinsic subtype (Luminal A, Luminal B, HER2-enriched, or Basal-like) and risk of recurrence with proliferation score (ROR-P, high vs. med/low). Euclidean distances between samples were calculated across the 50 genes, and the distribution of Euclidean distances were compared for samples that were concordant vs. discordant for each multigene classifier for PAM50 or ROR-P. Results Of the 37 tumors, 11 had samples with discordant PAM50 subtype and 7 had samples with discordant ROR-P group (75% and 83% agreement, respectively). The Euclidean distance between paired samples with discordant PAM50 intrinsic subtype or ROR-P score was significantly greater than that among concordant tumors. Samples discordant for ROR-P had more heterogeneity in histological characteristics, while discordance of PAM50 subtype call was generally not predicted by heterogeneity of these histological characteristics. Conclusion The concordance of PAM50 subtype calls and ROR-P, despite oversampling of heterogenous-appearing tumor regions, demonstrates reproducibility of the PAM50 classifier for breast cancer tumor intrinsic subtyping. However, assay sampling strategies for histologically heterogeneous tumors merit further consideration. Citation Format: Amber N. Hurson, Alina Hamilton, Linnea T. Olsson, Erin L. Kirk, Benjamin C. Calhoun, Joseph Geradts, Mark E. Sherman, Melissa A. Troester. Intratumoral heterogeneity of prognostic multigene signatures for breast cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference on Tumor Heterogeneity: From Single Cells to Clinical Impact; 2020 Sep 17-18. Philadelphia (PA): AACR; Cancer Res 2020;80(21 Suppl):Abstract nr PO-068.

Background: Tumor infiltrating lymphocytes (TILs) play an important, but incompletely understood role in chemotherapy response and prognosis. In breast cancer, there appear to be distinct immune responses by subtype, but most studies have used limited numbers of protein markers or bulk sequencing of RNA to characterize immune response, in which spatial organization cannot be assessed. Methods: To identify immune phenotypes of Basal-like vs. Luminal breast cancer we used the GeoMx® (NanoString) platform to perform digital spatial profiling (DSP) of immune-related proteins in tumor whole sections and tissue microarrays (TMA). Visualization of CD45, CD68, or pan-Cytokeratin by immunofluorescence was used to select regions of interest (ROIs) in formalin-fixed paraffin embedded tissue sections. 44 antibodies representing stromal markers and multiple immune cell types were applied to quantify the tumor microenvironment. Results: In whole tumor slides, immune hot spots (CD45+) had increased expression of many immune markers, suggesting a diverse and robust immune response. In epithelium-enriched areas, immune signals were also detectable and varied by subtype, with Regulatory T cell (Treg) markers (CD4, CD25, FOXP3) being higher in Basal-like vs. Luminal breast cancer. Extending these findings to TMAs with more patients (n=75), we confirmed subtype-specific immune profiles, including enrichment of Treg markers in Basal-likes. Conclusion: This work demonstrated that immune responses can be detected in epithelium-rich tissue, and that TMAs are a viable approach for obtaining important immunoprofiling data. In addition, we found that immune marker expression is associated with BC subtype, suggesting possible prognostic or targetable differences. Citation Format: Andrea Walens, Linnea T. Olsson, Xiaohua Gao, Alina M. Hamilton, Erin L. Kirk, Stephanie M. Cohen, Bentley R. Midkiff, Yongjuan Xia, Mark E. Sherman, Nana Nikolaishvili-Feinberg, Katherine A. Hoadley, Melissa A. Troester, Benjamin C. Calhoun. Protein-based immune profiles of basal-like vs luminal breast cancers [abstract]. In: Proceedings of the AACR Virtual Special Conference on Tumor Heterogeneity: From Single Cells to Clinical Impact; 2020 Sep 17-18. Philadelphia (PA): AACR; Cancer Res 2020;80(21 Suppl):Abstract nr PO-090.

Background: High levels of tumor infiltrating lymphocytes have been associated with favorable prognosis in triple negative and HER2-positive breast cancer (BC), especially in tumors with high mutation burden. Recently, our group showed that TP53 functional defects are strongly associated with black race in the Carolina Breast Cancer Study (CBCS). However, the immune microenvironment has been inconsistently associated with racial disparities in BC. Methods: To characterize immune phenotypes in BC, we curated a 50-gene NanoString immune panel and validated the gene set using RNA sequencing data from The Cancer Genome Atlas (TCGA). We applied the NanoString panel in the CBCS and estimated associations with immune infiltrates, BC intrinsic subtype, proliferation scores, p53 mutation signature and race using relative frequency differences (RFDs) as the measure of association. Results: Our 50-gene immune panel produced sample groupings in TCGA similar to that observed with the deconvolution algorithm, CIBERSORT. In CBCS (n=1208), we identified three immune groups primarily defined by features related to either adaptive immunity, innate immunity, or a quiet immune environment. Confirming that our expression-based groups reflect the tumor immune microenvironment, these immune groups correlated with histological evidence of immune cells from H&E slides in both TCGA and CBCS. The adaptive-enriched group was strongly associated with young age (≤50 years), high tumor grade, higher proliferation scores and the basal-like intrinsic subtype. TP53 mutant-like status was strongly associated with the adaptive-enriched immune group (RFD: 25.3%, p Conclusions: Our immune panel defines groups of BCs according to type of immune infiltration. Consistent with previous literature, we show that adaptive immunity is associated with aggressive breast tumors in CBCS. In addition, our data suggest an immunomodulatory effect of TP53 functional status–a variable we have previously associated with race in the CBCS. We provide evidence for a role of the immune microenvironment in racial disparities of BC. Further characterization of individual immune cell populations by race could reveal potential targets for BC intervention strategies that improve survivorship disparities. Citation Format: Alina M. Hamilton, Linnea T. Olsson, Benjamin C. Calhoun, Katherine A. Hoadley, Melissa A. Troester. Association of immune microenvironment and race in the Carolina Breast Cancer Study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1184.

Breast cancer is the second leading cause of cancer-related deaths in women in the United States. Although breast cancer mortality rates have dropped over the last few decades, the mortality rate for Black women is still 40% higher than White women. Even among the breast cancer subtype with the best prognosis (ER+/HER2-), Black women still have a higher risk of recurrence (ROR) by PAM50. Some work has been done to uncover differences in the biology of breast cancer between White and Black women, but there has been little study of how immune responses differ by race. To identify spatial relationships between tumor and specific immune subpopulations in the microenvironment of breast cancer, we used the GeoMx (NanoString) platform to perform digital spatial profiling (DSP) of tumor whole sections and tumor microarrays (TMA) from the Carolina Breast Cancer Study (CBCS), a large population-based study that oversampled for Black and younger women. DSP identifies relationships among immune subpopulations, analyzing approximately 40 immune markers in areas selected for CD45, CD68, or pan-cytokeratin content. Thus regions of interest (ROIs) can be selected to evaluate immune ‘hot spots' and the tumor microenvironment, separately. In whole tumor slides, we found that immune hot spots (high CD45 infiltrated ROIs) had elevated expression of many immune markers, suggesting that there was a widespread, robust immune response that included Macrophages, Dendritic cells, and B-cells in addition to T-cells. However, we also observed that immune markers were detectable in tumor-enriched areas, and that tumor-enriched areas had distinct immune signals depending upon subtype, with Regulatory T cell (Treg) markers being higher in Basal-like breast cancers and Dendritic cell markers being higher in Luminal A breast cancers. Extending these findings to tumor-enriched ROIs on TMAs, we evaluated 76 patients and once again found subtype-specific immune responses, including enrichment of Treg markers in Basal-like breast cancers. Receiver operating characteristic (ROC) analysis of Treg marker expression as a predictor for Basal-like versus Luminal A breast cancer had an area under the curve (AUC) score of 0.754, pointing to Treg markers as an effective predictor of breast cancer subtype. With DSP analysis, immune marker expression can elucidate spatial differences in the tumor microenvironment and predict breast cancer subtype and other clinicopathologic and prognostic features. Our data demonstrates that both whole slide and TMA specimens can be used to understand the breast cancer microenvironment by subtype. The contribution of race to these immune responses will require larger numbers of tumors of specific subtypes, as there are strong immune response differences by subtype. Citation Format: Andrea Walens, Linnea Olsson, Xiaohua Gao, Alina Hamilton, Erin Kirk, Katherine Hoadley, Ben Calhoun, Melissa Troester. Uncovering spatial relationships of the tumor microenvironment in the Carolina Breast Cancer Study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5389.

Background: Clear cell renal cell carcinoma (ccRCC) is the most common type of RCC, making up over 80% of cases. Two molecular ccRCC subtypes, designated ccA and ccB, have been well characterized as having prognostic relevance, with ccB tumors associated with poorer survival. However, no epidemiologic studies to date have investigated whether these molecular subtypes possess distinct risk factors. We explored the possible existence of etiologic heterogeneity for ccA and ccB tumors within a multi-center hospital-based case-control study of kidney cancer conducted in Central and Eastern Europe. Methods: We measured mRNA expression for a 34-gene ccA/ccB classification panel (ClearCode34) in tumor samples collected from 333 ccRCC cases. Using TCGA-KIRC data as a training set, we predicted ccA/ccB status using prediction analysis of microarrays and restricted our data analysis to tumors with a predicted subtype probability >70% (n=262). We used logistic and polytomous regression modeling to compute odds ratios (OR) and 95% confidence intervals (CI) to assess subtype differences by age and sex (via case-only analyses) and, through comparisons between cases and controls (N=1,476), subtype-specific ORs for established RCC risk factors. We also conducted a meta-analysis combining our case-only findings for sex and body mass index (BMI) with those from three clinical studies with ccRCC molecular classification. Results: Cases with ccB tumors (n=111) were more likely than those with ccA tumors (n=151) to be male (OR 2.6, 95% CI 1.4-4.7 controlling for country, age at diagnosis, stage and grade). In case-control analyses, ccA tumors were more strongly associated with moderate and severe obesity (OR 2.1, 95% CI 1.3-3.5 and 2.5, 1.2-5.2 for BMI 30.0-34.9 and ≥35.0 vs. Conclusions: Our findings suggest that the etiology of ccRCC may be more complex than previously understood, with evidence of differences across molecular subtypes in their relationships with sex, obesity, trichloroethylene exposure and genetic susceptibility. Citation Format: Mark P. Purdue, Jongeun Rhee, Lee Moore, Xiaohua Gao, Xuezheng Sun, Erin Kirk, Catherine Callahan, Vladimir Bencko, Vladimir Janout, Dana Mates, Lenka Foretova, Neonilia Szeszenia-Dabrowska, Vsevolod Matveev, David Zaridze, Stacey Petruzella, A. Ari Hakimi, Maria Merino, W. Marston Linehan, Paul Brennan, Helena Furberg, Melissa Troester, Nathaniel Rothman. Differences in risk factors for molecular subtypes of clear cell renal cell carcinoma in a case-control study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2340.

Background: To date, most genome-wide association studies (GWAS) of breast cancer have been conducted only among women of Asian and European ancestry. It is difficult to generalize results from those studies to women of African ancestry (AA). We conducted a large genetic association study of breast cancer in women of AA by analyzing both genetic and transcriptomic data. Methods: This collaborative study included 11,073 cases and 11,095 controls of AA who were participants in more than 15 studies conducted in the U.S. and Africa. Genotyping data were harmonized and imputed using the 1000 Genomes Project database as the reference. Imputed genotypes were used for GWAS to identify novel genetic risk loci for breast cancer. To search for susceptibility genes, we conducted a transcriptome-wide association study (TWAS), in which gene expression prediction models were built using genetic and tumor tissue RNA sequencing data from ~400 AA patients and used to impute expression levels of genes across the transcriptome for association analyses in all cases and controls included in the GWAS mentioned above. Results: We identified five loci (5p15.33, 5q31.3, 10q26.13, 18q12.1, and 19p13.11) associated with breast cancer risk at P < 5 × 10−8, including a novel locus at 5q31.3 (allelic odds ratio, OR = 1.18, 95% CI = 1.11-1.25, P = 4.65 × 10−8, nearby gene, ARHGAP26). This locus was also identified in association with estrogen receptor (ER) positive breast cancer at P < 5 × 10−8. Analyses stratified by ER status replicated known loci associated specifically with ER-positive (10q26.13) or ER-negative (2q14.2, 2p11.2, 5p15.33) breast cancer at P < 5 × 10−8. Of the 165 lead risk SNPs reported from previous breast cancer GWAS, 35 SNPs were replicated with the same association direction at P < 0.05. We constructed a polygenic risk score using these 35 replicated SNPs and the lead risk SNP at the novel locus and estimated the AUC to be 0.575. Of the 7,592 genes tested in the TWAS, we identified one gene, AC091053.1, with an association at a Bonferroni-corrected threshold of 6.64 × 10−6 (0.05/7,592). AC091053.1 is a long non-coding RNA gene at locus 11p15.4, where no risk variants have been identified in any previous breast cancer GWAS. AC091053.1 is located in the region of protein coding gene DENND2B, which acts as a regulator of MAPK1/ERK2 kinase and reduces the tumorigenic phenotype in cells. The gene AC091053.1 was associated with ER-positive breast cancer with P = 4.11 × 10−5 and ER-negative breast cancer with P = 0.032. Conclusions: Our study, the largest genetic study conducted to date in AA, identified novel breast cancer risk loci at 5q31.3 and 11p15.4 (AC091053.1) among women of AA and replicated >30 associations reported in previous studies. Studies with a larger sample size are needed to further investigate genetic variants and genes associated with breast cancer risk in AA women. Citation Format: Guochong Jia, Jie Ping, Yaohua Yang, Maureen Sanderson, Qiuyin Cai, Xingyi Guo, William J. Blot, Bingshan Li, Elisa V. Bandera, Manjeet K. Bolla, Montserrat García-Closas, Douglas F. Easton, Mary K. Fadden, Jian Gu, Dezheng Huo, Esther M. John, Kathryn L. Lunetta, Olufunmilayo I. Olopade, Xiang Shu, Melissa A. Troester, Song Yao, Breast Cancer Association Consortium, Andrew F. Olshan, Christine B. Ambrosone, Christopher A. Haiman, Jirong Long, Julie R. Palmer, Wei Zheng. Integrating genomic and transcriptomic data to identify genetic loci associated with breast cancer risk in women of African ancestry [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 28.

Background: Over 180 genetic variants have been identified as risk loci for breast cancer. However, most loci were discovered using European ancestry populations. As some common susceptibility loci are shared across populations, we aim to discover new risk loci for breast cancer using a cross-ancestry genome-wide association study (GWAS) approach. Methods: Data from five GWAS studies in women of African ancestry with a combined sample size of 9241 cases and 10192 controls were used to generate pooled breast cancer risk estimates in a fixed effect meta-analysis, and this served as the discovery dataset. Summary statistics from the GWAS conducted in European ancestry populations (Breast Cancer Association Consortium, 122977 cases and 105974 controls) served as the validation dataset. The variants that were associated with breast cancer risk at P < 0.01 in the GWAS of African ancestry were meta-analyzed with the GWAS in European ancestry. A locus was considered novel if the lead index variant was genome-wide significant (5 × 10−8) in the cross-ancestry meta-analysis and >500kb away from known breast cancer risk loci. Conditional on the lead index variants, we searched for additional signals in each locus using multivariable logistic regression. Analyses were done separately for ER-positive, ER-negative and overall breast cancer risk. Results: We discovered four novel loci for overall breast cancer risk (1p13.3, 5q31.1, 15q24, and 15q26.3) and two novel loci for ER-negative breast cancer (1q41 and 7q11.23) at the genome-wide significance level of P < 5 × 10−8. Three index single nucleotide polymorphism (SNPs) lie within introns of genes (KCNK2, C5orf56, and SIN3A) and the other index SNPs are located in intergenic regions (close to GSTM4 and AMPD2, CASTOR2, and the antisense DNA RP11-168G16.2). The direction of the associations was consistent between the GWASs of African and European descendants. At the 15q24 locus, we found an additional SNP (in the intron of the SCAMP2 gene) to be independently associated with overall breast cancer risk. Conclusions: We have identified six new risk loci that may contribute to better prediction of breast cancer risk in African ancestry populations and provide new insights into mechanisms of breast cancer carcinogenesis. Replication of these loci in multiple populations and functional studies can help to identify causal variants. Citation Format: Babatunde Adedokun, Zhaohui Du, Guimin Gao, Thomas Ahearn, Kathryn L. Lunetta, Gary Zirpoli, Jonine Figueroa, Esther M. John, Leslie Bernstein, Wei Zheng, Jennifer J. Hu, Regina G. Ziegler, Sarah Nyante, Elisa V. Bandera, Sue A. Ingles, Michael F. Press, Sandra L. Deming, Jorge L. Rodriguez-Gil, Song Yao, Temidayo O. Ogundiran, Oladosu Ojengbede, William Blot, Melissa Troester, Katherine L. Nathanson, Anselm Hennis, Barbara Nemesure, Stefan Ambs, Lara E. Sucheston-Campbell, Jeannette T. Bensen, Stephen J. Chanock, Andrew F. Olshan, Christine B. Ambrosone, David V. Conti, Olufunmilayo I. Olopade, Montserrat Garcia-Closas, Julie R. Palmer, Christopher A. Haiman, Dezheng Huo. Cross-ancestry genome-wide association study identifies six new loci for breast cancer in women of African and european ancestry [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4613.

Background: A polygenic risk score (PRS) for breast cancer including 313 common variants developed by the Breast Cancer Association Consortium (BCAC) has been demonstrated to identify women who are at high risk of developing breast cancer [odds ratio (OR 95%CI) = 1.61 (1.57-1.65) per SD] in women of European ancestry. In the present study, we examined the performance of the 313-variant PRS and a PRS including 179 variants reaching genome-wide significance in previous genome-wide association studies (GWAS), in women of African ancestry. Methods: We assembled genotype data for women of African ancestry from 28 breast cancer studies, including a total of 9,241 cases and 10,193 controls. We constructed the 179-variant and 313-variant PRSs with relative risk weights for each variant estimated in women of European ancestry in BCAC. The associations between the two PRSs and overall, ER+ and ER- breast cancer risk were estimated using logistic regression adjusting for age, study site and principal components. Discriminatory accuracy of the PRSs was evaluated using the receiver operating characteristic curve (AUROC). We then recalibrated the 179-variant PRS by replacing index variants with variants in each region that better captured risk in women of African ancestry and used relative risk weights estimated in women of African ancestry. We also assessed PRS performance by age ( Results: Both the 179 and 313- variant PRSs were significantly associated with overall, ER+ and ER- breast cancer risk, with odds ratios (OR) per standard deviation of 1.21~1.37 and AUROCs ranging from 0.57 to 0.59. The 179-variant PRS outperformed in ER- cancer [1.31(1.24,1.37) per SD] while the 313-SNP PRS was better for overall [1.27(1.23,1.31) per SD] and ER+ cancer [1.37(1.32,1.43) per SD]. For overall breast cancer, compared to women with average risk (40th-60th PRS percentiles), women in the top decile of PRS had a 1.54 (95% CI: 1.38, 1.72)-fold increased risk. The performance of the recalibrated 179-variant PRS was not improved (average AUROC=0.56). The PRS ORs did not differ significantly across age strata (P-value for age interaction = 0.63). Conclusion: Our study shows that both 179 and 313 variant PRS stratify breast cancer risk in women of African ancestry, with attenuated performance compared to that reported in European and in Latina populations. Future work is needed to improve breast cancer risk stratification for women of African ancestry. Citation Format: Zhaohui Du, Guimin Gao, Babatunde Adedokun, Thomas Ahearn, Kathryn L. Lunetta, Gary Zirpoli, Melissa Troester, Edward A. Ruiz-Narváez, Stephen Haddad, Jonine Figueroa, Esther M. John, Leslie Bernstein, Wei Zheng, Jennifer J. Hu, Regina G. Ziegler, Sarah Nyante, Elisa V. Bandera, Sue A. Ingles, Michael F. Press, Sandra L. Deming, Jorge L. Rodriguez-Gil, Song Yao, Temidayo O. Ogundiran, Oladosu A. Ojengbede, William Blot, Katherine L. Nathanson, Anselm Hennis, Barbara Nemesure, Stefan Ambs, Lara E. Sucheston-Campbell, Jeannette T. Bensen, Stephen J. Chanock, Andrew F. Olshan, Christine B. Ambrosone, David V. Conti, Olufunmilayo I. Olopade, Julie R. Palmer, Montserrat Garcia-Closas, Dezheng Huo, Christopher A. Haiman. Evaluating a polygenic risk score for breast cancer in women of African ancestry [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2320.

Purpose: Understanding breast cancer mortality disparities by race and age is complex due to disease heterogeneity, comorbid disease, and the range of factors influencing access to care. We compared socioeconomic status (SES) and comorbidity factors from the Carolina Breast Cancer Study Phase III (CBCS3, 2008-2013) to North Carolina and examined factors related to race and age in CBCS. Methods: Distributions of SES and comorbidity factors in CBCS3 cases were compared to those of North Carolina women in the 2010 Behavioral Risk Factor Surveillance Study. Using latent class analysis of CBCS3 data, we identified covariate patterns by SES/comorbidities, barriers to care, and tumor characteristics and examined their associations with race and age using multinomial logistic regression. Results: Major SES and comorbidity patterns in CBCS3 participants were generally similar to patterns in the state. Latent classes were identified for SES/comorbidities, barriers to care, and tumor characteristics that varied by race and age. Compared to white women, black women had lower SES (odds ratio (OR)=6.3, 95% confidence interval (CI); 5.2, 7.8), more barriers to care (OR=5.6, 95% CI; 3.9, 8.1) and several aggregated tumor aggressiveness features. Compared to older women, younger women had higher SES (OR=0.5, 95% CI; 0.4, 0.6), more barriers to care (OR=2.1, 95% CI; 1.6, 2.9) and aggregated tumor aggressiveness features. Conclusions: CBCS3 is representative of North Carolina on comparable factors. Patterns of access to care and tumor characteristics are intertwined with race and age, suggesting that interventions to address disparities will need to target both access and biology. Citation Format: Marc A Emerson, Yvonne M Golightly, Xianming Tan, Allison E Aiello, Katherine E Reeder-Hayes, Andrew F Olshan, Shelley A Earp, Melissa Troester. Developing an integrated understanding of access to care and tumor characteristics patterns by race and age in the Carolina Breast Cancer Study Phase III, 2008 – 2013 [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B100.

Background: Women who have at least one first-degree relative diagnosed with breast cancer have an almost two-fold risk of developing breast cancer themselves. Therefore, there is particular interest in identifying modifiable factors that can reduce risk. To date, most studies of breast cancer risk in women with a family history of breast cancer have focused on White women. Methods: We pooled questionnaire data on Black women from three case-control studies (Women’s Contraceptive and Reproductive Experiences, Carolina Breast Cancer Study, and Women’s Circle of Health Study) and nested case-control data from the prospective Black Women’s Health Study for an analytic sample of 5,015 invasive breast cancer cases and 15,354 controls; 15.9% of cases and 9.4% of controls reported a first-degree family history of breast cancer (“family history”). We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for risk of breast cancer overall, and by estrogen receptor (ER) status, within strata of family history. All models were adjusted for age and study. Additional covariates were body mass index (recent and at age 18), adult height, smoking, alcohol consumption, parity, breastfeeding, age at first birth, age at menarche, interval between menarche and first birth, age at menopause, and history of benign breast disease. Results: ORs were consistent among women with and without a family history for most factors. However, associations of parity and breastfeeding with risk of ER negative breast cancer were stronger among women with a positive family history: the OR for ever parous vs. nulliparous was 1.63 (1.11-2.39) among women with a family history and 1.31 (1.13-1.53) among those without. In both groups, the elevated OR associated with parity was reduced if the women had breastfed at least one child. The ORs for ER negative breast cancer associated with parity without breastfeeding were 1.86 (1.25-2.77) and 1.43 (1.22-1.67), among women with and without a family history of breast cancer, respectively (p-interaction >0.05). Additional control for other reproductive factors did not materially change the estimates. Breastfeeding was not associated with risk of ER positive breast cancer in either group. Conclusion: As has been shown previously, parous women were found to be at increased risk of ER negative breast cancer, with the increase attenuated by breastfeeding. Stratification by family history of breast cancer indicated that the associations may be stronger among women with a first-degree family history, although interactions were not statistically significant. Findings from the present study demonstrate that Black women who already have a higher than average baseline risk of ER negative breast cancer due to their familial history may favorably modify their risk by breastfeeding. Citation Format: Gary R Zirpoli, Traci N Bethea, Leslie Bernstein, Melissa A Troester, Christine B Ambrosone, Julie R Palmer. Breast cancer in Black women: Do risk factors differ for those who have a family history of breast cancer? [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D101.

Background: Polychlorinated biphenyls (PCBs) are a group of 209 synthetic organic chemicals, several of which are known carcinogens or endocrine disruptors. PCBs are hypothesized to influence the risk of developing breast cancer; however, whether PCBs influence the risk of mortality following breast cancer is poorly understood. We examined plasma levels of 17 PCB congeners in association with mortality among women who participated in the population-based Carolina Breast Cancer Study (CBCS). Methods: Participants included 456 white and 292 black women who were diagnosed with primary invasive breast cancer from 1993-1996, and who had PCB and lipid measurements from blood samples obtained on average 4.1 months after diagnosis. Using the National Death Index, we identified 392 deaths including 210 from breast cancer, over a median follow-up of 20.6 years. We used Cox regression to estimate covariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and breast cancer-specific 5-year mortality, and 20-year mortality conditional on 5-year survival in relation to tertiles and continuous ln-transformed lipid-adjusted PCB levels. We also examined effect measure modification by race. Results: The highest (vs. lowest) tertile of PCB118 was associated with a 5-year breast cancer-specific mortality HR of 1.86 (95% CI=1.07-3.23). One-ln unit increases in PCB74, PCB99, PCB118, and total PCBs were associated with 5-year breast cancer-specific mortality HRs ranging from 1.33 (95% CI=1.02-1.74) for PCB74 to 1.40 (95% CI=1.02-1.92) for PCB118. By race, a one-ln unit increase in PCB74 was associated with a HR of 1.47 (95% CI=1.01-2.14) among black women and with a HR of 1.19 (95% CI=0.79-1.77) among white women (P-Interaction=0.05). Continuous PCB levels were associated with 20-year conditional all-cause mortality HRs ranging from 1.20 (95% CI=1.03-1.41) for a one-ln unit increase in PCB182+PCB187 to 1.37 (95% CI=1.12-1.68) for a one-ln unit increase in PCB118. PCBs were not associated with 5-year all-cause mortality or with 20-year conditional breast cancer-specific mortality. Conclusion: PCBs may increase the risk of short-term breast cancer-specific mortality as well as long-term all-cause mortality among women with breast cancer. Citation Format: Humberto Parada, Xuezheng Sun, Chiu-Kit Tse, Lawrence S. Engel, Andrew F. Olshan, Melissa A. Troester. Plasma levels of polychlorinated biphenyls (PCBs) and breast cancer mortality: The Carolina Breast Cancer Study [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D095.

Introduction: Cooking meat at high temperatures and charring of meat increases the production of heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), which are implicated in breast carcinogenesis. Several epidemiologic studies have reported increased risk of breast cancer with higher intake of HCAs or red meat intake. However, few studies have examined these associations in racially diverse populations. The goal of the study was to examine the associations between various meat and fish preparation methods and breast cancer using the Carolina Breast Cancer Study (CBCS) Phase 2. Methods: African American (AA) and European American (EA) women aged 20-74 years with a first diagnosis of invasive or in situ breast cancers were enrolled. Controls were identified through the DMV and Medicare lists and were frequency matched to cases by race and age group (AA: 548 cases and 452 controls; EA: 858 cases and 748 controls). Preparation methods and intake frequencies were obtained through self-report questionnaires. Multivariable logistic regression analysis was used to obtain odds ratios and 95% CIs of breast cancer by frequency of intake of meat and fish cooked by various preparation methods. Results: Using no reported meat intake as the referent, positive associations with breast cancer were observed for intakes of grilled/barbecued hamburger (one or more times per week, OR: 1.30; 95% CI: 1.02, 1.66), and for pan-fried/oven-broiled beef steak (one or more times per week, OR: 1.38; 95% CI: 1.09, 1.74). Inverse associations with breast cancer were observed for pan-fried fish (one or more times per week, OR: 0.77; 95% CI: 0.61, 0.99) and for grilled/barbecued pork chops (OR: 0.82, 95% CI: 0.69, 0.98). Overall, the associations appeared to be stronger among EA women but showed inconsistency within meat categories (fish, pork, beef) depending upon method of cooking. Conclusion: Among AA and EA women, more frequently consuming beef prepared with high-temperature methods (such as grilling or oven-broiling) was associated with higher odds of breast cancer, and the associations were stronger among EA women compared to AA women. In contrast, consuming pan-fried fish or grilled/barbecued pork chops weekly was associated with lower odds of breast cancer compared to less frequent consumption. Citation Format: Omonefe Omofuma, Susan Steck, Melissa Troester, Andrew Olshan. Meat and fish intake and the risk of breast cancer in the Carolina Breast Cancer Study (CBCS) [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C043.

Background: Black women have higher breast cancer mortality than white women, particularly within the hormone receptor positive, human epidermal growth factor receptor 2 negative (HR+/HER2-) clinical subtype. Interactions between tumor biology and treatment factors are complex and racial disparities in early events (such as 5-year recurrence risk) are not well characterized. Methods: Using data from the Carolina Breast Cancer Study (Phase 3, 2008-2013), a large population-based study enrolling 50% black and 50% white women from 44 counties in North Carolina, we estimated associations between race and recurrence among non-metastatic HR+/HER2- tumors, overall and within subgroups defined by PAM50 Risk of Recurrence score (ROR-PT, calculated from subtype, proliferation level, and tumor size), PAM50 intrinsic subtype, and tumor grade. We also compared treatment patterns by race among HR+/HER2- patients with high-risk disease. Relative frequency differences (RFD), interpretable as the percentage difference between index and referent groups, were estimated using multivariable linear regression. Recurrence risk was estimated using survival curves standardized for age and stage and inverse probability-weighted Cox models. Results: Among 1,775 eligible women, black women had higher recurrence risk relative to white women (crude hazard ratio: 1.8, 95% confidence interval [CI]: 1.3, 2.5), which remained elevated after standardizing for age and clinical covariates (hazard ratio: 1.4, CI: 1.0, 1.9). In stratified analyses, racial disparities persisted among women with high ROR-PT score (5-year standardized recurrence risk 18.9% in black vs. 12.5% in white women) and in high grade patients (5-year standardized recurrence risk 16.6% in black vs. 12.0% in white women). Black women with high grade tumors were significantly less likely to initiate endocrine therapy (RFD: -8.4%, CI: -15.9, -1.0) and experienced treatment delay more often than white women (RFD: +10.4%, CI: 1.8, 19.0). Conclusions: Racial disparities in HR+/HER2- breast cancer recurrence persist within high-risk subgroups. Efforts to identify treatment inequities and other causes of variation in cancer treatment are critical to reducing outcome disparities. Note: This abstract was not presented at the conference. Citation Format: H. Shelton Earp, Andrew F Olshan, Lisa A Carey, Charles M Perou, Melissa A Troester, Halei C. Benefield, Katherine E Reeder-Hayes, Hazel B Nichols, Benjamin C Calhoun, Michael I Love, Xuezheng Sun, Erin L Kirk, Joseph Geradts, Katherine A Hoadley, Stephen R Cole. Outcomes of hormone-receptor positive, HER2-negative breast cancers by race and tumor biologic features [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C045.

In the US, bilateral oophorectomies are frequently performed before menopause for one of two reasons: 1) in concert with hysterectomy for benign gynecologic conditions or 2) prevention of breast or ovarian cancer risk and mortality. Prior literature has consistently shown a reduction in breast cancer-specific mortality among women who had premenopausal hysterectomy with bilateral oophorectomy (H +BO) prior to their breast cancer diagnosis. The present study sought to assess whether the relationship between prediagnosis premenopausal H + BO and breast cancer-specific mortality differed by family history status in women with breast cancer. It is hypothesized that women who may have prognostically different breast cancer due to having family history disproportionately benefit from premenopausal H+ BO compared to more average-risk women with no family history. This study analyzed data from Phases 1 and 2 of the Carolina Breast Cancer Study (CBCS), a population-based study of Black and White women prospectively identified in central and eastern North Carolina with newly diagnosed breast cancer between 1993 and 2001. Women with invasive breast cancer with known gynecologic surgical status were included (n=1,723). Gynecologic surgery was defined as: no surgery; hysterectomy with bilateral oophorectomy (H+BO); hysterectomy with conservation of ≥1 ovary (H + OC). Cause-specific mortality was ascertained using the National Death Index, last updated in 2016. Hazard ratios (HR) and 95% confidence intervals (CI) for breast cancer-specific mortality were estimated with Cox proportional hazard models. Models were then stratified by family history status, the self-reporting of one or more first-degree relatives with a family history of breast cancer. Models were adjusted for race, age at diagnosis, smoking, alcohol use, menopausal hormone therapy use and reproductive history factors. All participants still living at the end of follow-up were right censored. Among 1,723 women in the sample, 44% (n=759) were Black and 56% (n=964) were White. There were 836 deaths, of which 447 were from breast cancer. In this population, 74.1% (n=1,276) of women reported having no previous premenopausal gynecologic surgery, 8.8% (n=152) reported having H + BO and 17.1% (n=295) reported H + OC. Compared to women who had not had premenopausal gynecologic surgery, the overall adjusted HR for breast cancer-specific mortality associated with H+BO was 0.68 (95% CI: 0.49,0.96) and 0.90 (95% CI: 0.72,1.12) for women with H+OC. In models stratified on family history, the HR for women with H+BO was 0.11 (95% CI: 0.03,0.42) for those with family history and 0.90 (95% CI: 0.63, 1.29) for those without. The HR for women with family history who had H+ OC was 0.77 (95% CI: 0.45, 1.29) and 0.90 (95% CI: 0.63,1.29) for women without. This study suggests that the overall protective relationship observed between premenopausal hysterectomy with bilateral oophorectomy and breast-cancer specific mortality may be driven by a small subset of especially high-risk women. Citation Format: Mya L. Roberson, Whitney R. Robinson, Hazel B. Nichols, Andrew F. Olshan, Melissa A. Troester. Premenopausal oophorectomy and survival among women with breast cancer: Evidence of effect measure modification by family history status [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C052.

The relationship between germline genetic variation and breast cancer survival is largely unknown, especially in understudied minority populations. Traditional genome-wide association studies (GWAS) have interrogated survival associations in cohorts of predominantly European ancestries but are often underpowered due to subtype heterogeneity in breast cancer and a wide range of clinical covariates. Furthermore, these analyses tend to detect loci in non-coding regions, which require follow-up functional studies to interpret. Recent work in transcriptome-wide association studies (TWAS) has shown increased power in detecting functionally-relevant, trait-associated loci by leveraging information from expression quantitative trait loci (eQTLs) in external reference panels in relevant tissues. However, race-specific reference panels for TWAS may be needed to draw correct inference in large, ethnically-heterogeneous cohorts, and such panels for breast cancer are lacking. In this work, we provide a framework for TWAS for breast cancer in diverse populations, using data from the Carolina Breast Cancer Study (CBCS), a population-based cohort that oversampled for women self-identifying as African American. Using Nanostring expression data from CBCS, we perform an eQTL analysis for 417 breast cancer-related genes to train race-stratified predictive models of tumor expression from germline genotypes. We use these models to impute expression in held-out samples from the CBCS and in The Cancer Genome Atlas, using a permutation method to assess predictive performance accounting for sampling variability. We find that these race-stratified expression models are not always applicable across race, depending on the imputation cohort. Furthermore, their predictive performance varies by breast cancer subtypes. Lastly, we conduct a small-scale TWAS for breast cancer mortality in CBCS (N = 3,828), controlling for covariates used in previous GWAS for breast cancer survival. At an false discovery rate-adjusted P-value less than 0.1, adjusting for self-reported race, we find hazardous associations near CAPN13 (2p23.1), VAV3 (1p13.3), and BLK (8p23.1) and a protective association near SERPINB5 (18q21.33) in TWAS that are underpowered in GWAS. This approach shows increased power for detection of survival-associated genomic loci, demonstrating the relative strength of TWAS over GWAS. A carefully implemented TWAS is an efficient alternative to GWAS for understanding the genetic architecture underpinning breast cancer outcomes in diverse human populations and across biologically distinct tumor types. Citation Format: Arjun Bhattacharya, Montserrat García-Closas, Andrew F. Olshan, Charles M. Perou, Melissa A. Troester, Michael I Love. A framework for transcriptome-wide association studies in breast cancer in diverse study populations [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B065.

TPS1597 Background: This randomized trial is intended to determine whether tomosynthesis (TM) should replace the current standard for breast cancer (BC) screening, digital mammography (DM). It is hypothesized that the population of women assigned TM screening for 3-5 rounds will have fewer advanced cancers than the population assigned to DM screening. Methods: 164,946 women, ages 45 to 74 years who present for screening mammography and consent to participate will be enrolled across 150 sites in the US, Canada and abroad. Women will be randomized to TM or DM. The frequency and number of screening examinations over a five year period will vary based on menopausal status and whether they have specific risk factors, including - hormone use, family history of BC, deleterious genes, prior benign breast biopsy with diagnosis of LCIS or atypia any kind, or dense breasts. Blood and buccal cells will be collected from as many enrolled women as are willing to provide the samples. All breast biopsies during the trial will undergo gene expression analysis for the PAM50 and other progression pathways (PAM50-plus). All subjects enrolled will be followed long term for at least eight years. The primary endpoint is the proportion of participants who have an advanced breast cancer diagnosed at any time within 4.5 years of randomization in to the trial. Secondary endpoints include measures of diagnostic and predictive performance; rates of recall, biopsy, and interval cancers, prevalence of breast cancer subtypes, and tumor subtype based on PAM50-plus analysis. As of January 17th 2020, there are 104 sites open and 21,452 women enrolled in the trial. The DSMC last reviewed the trial in June 2019 and suggested that the trial continue as planned. Clinical trial information: NCT03233191.

BACKGROUND Workers raised concerns over suspected excesses of mortality at automotive electronics manufacturing facilities in Huntsville, Alabama. METHODS A study of 4396 UAW members ever-employed at Huntsville facilities between 1972 and 1993 was conducted with mortality follow-up through 2016. Standardized Mortality Ratios (SMRs) were estimated using U.S. and Alabama reference rates. RESULTS Relative to U.S. rates, there was a modest excess of all-cause mortality among White female workers (SMR 1.08, 95%CI: 0.99-1.18) and among all workers hired

ObjectivesUranium miners in Příbram, Czech Republic were exposed to low and moderate levels of radon gas and other hazards. It is unknown whether these hazards increase the risk of mortality or cancer incidence when compared with the general Czech population.MethodsA cohort of 16 434 male underground miners employed underground for at least 1 year between 1946 and 1976, and alive and residing in the Czech Republic in 1977, were followed for mortality and cancer incidence through 1992. We compared observed deaths and cancer incidence to expectation based on Czech rates. Standardised mortality ratios (SMRs), standardised incidence ratios (SIRs) and causal mortality ratios were calculated.ResultsUnderground workers in the Příbram mines had higher rates of death than expected due to all causes (SMR=1.23, 95% CI 1.20 to 1.27), all cancers (SMR=1.52, 95% CI 1.44 to 1.60), lung cancer (SMR=2.12, 95% CI 1.96 to 2.28) and extrathoracic cancer (SMR=1.41, 95% CI 1.15 to 1.77). Similar excess was observed in cancer incidence analyses, with the addition of stomach cancer (SIR=1.37, 95% CI 1.11 to 1.63), liver cancer (SIR=1.70, 95% CI 1.16 to 2.25) and rectal cancer (SIR=1.41, 95% CI 1.16 to 1.66). The SIR was elevated for all leukaemias (SIR=1.51, 95% CI 1.08 to 2.07) and for lymphatic and haematopoietic cancers combined (SIR=1.31, 95% CI 1.05 to 1.61), but results for specific subtypes were imprecise. Deaths due to hazardous mining conditions resulted in 0.33 person-years of life lost per miner.ConclusionsOccupational exposure to the Příbram mines resulted in excess cancers at several sites, including sites previously linked to radon and uranium exposure. Incidence analyses showed relative excess of several additional cancer subtypes.

BACKGROUND This study was carried out in response to worker concerns over their exposure to lead solder and chlorinated solvents at automotive electronics manufacturing plants in Huntsville, Alabama. METHODS A study of 4396 United Autoworkers members ever-employed at the plants between 1972 and 1993 was conducted with mortality follow-up through 2016. Poisson regression was used to estimate mortality rate ratios (RR) according to employment characteristics, including calendar period of employment. RESULTS Pre-1977 hires exhibited elevated adjusted rates of all-cause (RR, 1.29; 95% confidence interval [CI], 1.09-1.52), cardiovascular (RR, 1.38; 95% CI, 1.03-1.86), and digestive system (RR, 2.31; 95% CI, 1.04-5.10) disease mortality relative to the most recent hire group (1984-1993). Never- versus ever-employment in a skilled trade job was associated with elevated adjusted rates of all-cause, all-cancer, and cardiovascular disease mortality. Nervous system disorder mortality was greatest among 1977-1983 hires. CONCLUSIONS Elevated mortality among pre-1977 hires is consistent with worker concerns over greater exposure to hazards at the original plant building.

Several studies have sought to identify novel transcriptional biomarkers in normal breast or breast microenvironment to predict tumor risk and prognosis. However, systematic efforts to evaluate intra-individual variability of gene expression within normal breast have not been reported. This study analyzed the microarray gene expression data of 288 samples from 170 women in the Normal Breast Study (NBS), wherein multiple histologically normal breast samples were collected from different block regions and different sections at a given region. Intra-individual differences in global gene expression and selected gene expression signatures were quantified and evaluated in association with other patient-level factors. We found that intra-individual reliability was relatively high in global gene expression, but differed by signatures, with composition-related signatures (i.e., stroma) having higher intra-individual variability and tumorigenesis-related signatures (i.e., proliferation) having lower intra-individual variability. Histological stroma composition was the only factor significantly associated with heterogeneous breast tissue (defined as > median intra-individual variation; high nuclear density, odds ratio [OR] = 3.42, 95% confidence interval [CI] = 1.15–10.15; low area, OR = 0.29, 95% CI = 0.10–0.86). Other factors suggestively influencing the variability included age, BMI, and adipose nuclear density. Our results underscore the importance of considering intra-individual variability in tissue-based biomarker development, and have important implications for normal breast research.

Purpose: The use of combined estrogen-progestin menopausal hormone therapy (MHT) has been shown to increase the risk of breast cancer, however, recent observational studies have suggested that the association between MHT and breast cancer may be modified by race. The objective of this study was to investigate the association between MHT use and incidence of invasive breast cancer in Black and White women aged ≥40 years at diagnosis after accounting for racial differences in patterns of MHT use and formulation. Methods: Data from the Carolina Breast Cancer Study, a population-based case–control study of Black and White women in North Carolina conducted between 1993 and 2001, was used to analyze 1474 invasive breast cancer cases and 1339 controls using unconditional logistic regression. Results: Black women were less likely than White women to use any MHT and were more likely to use an unopposed-estrogen formulation. Combined estrogen-progestin MHT use was associated with a greater odds of breast cancer in White (adjusted odds ratio [OR] 1.48, 95% confidence interval [CI]: 1.03–2.13) and Black (OR 1.43, 95% CI: 0.76–2.70) women, although the estimate in Black women was imprecise. In contrast, use of unopposed-estrogen MHT among women with prior hysterectomy was not associated with breast cancer in women of either race. Conclusion: The association between MHT and invasive breast cancer appears to be similar in both Black and White women after accounting for differences in formulation and prior hysterectomy. These findings emphasize the importance of accounting for MHT formulation in race-stratified analyses of breast cancer risk.

PURPOSE: Metformin has been associated with a reduced incidence of prostate cancer and improved prostate cancer outcomes. However, whether race modifies the association between metformin use and prostate cancer aggressiveness remains uncertain. The association between metformin use and prostate cancer aggressiveness was examined separately in Black Americans (Blacks) and White Americans (Whites). METHODS: The study population consisted of 305 Black and 195 White research participants with incident prostate cancer and self-reported diabetes from the North Carolina-Louisiana Prostate Cancer Project (PCaP). High aggressive prostate cancer was defined using a composite measure of Gleason sum, prostate-specific antigen, and clinical stage. Multivariable logistic regression was used to assess the association between metformin use and high aggressive prostate cancer at diagnosis, separately among Whites and Blacks, with adjustment for age, screening history, site, education, insurance, and body mass index. RESULTS: Metformin use was associated positively with high aggressive prostate cancer in Blacks (OR: 2.01; 95% CI: 1.05, 3.83). By contrast, a weak inverse association between metformin use and high aggressive prostate cancer was found in Whites (OR: 0.80, 95% CI: 0.34, 1.85). CONCLUSIONS: The association between metformin use and prostate cancer aggressiveness may be modified by race.

Background Breast cancer subtype can be classified using standard clinical markers (estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2)), supplemented with additional markers. However, automated biomarker scoring and classification schemes have not been standardized. The aim of this study was to optimize tumor classification using automated methods in order to describe subtype frequency in the African American Breast Cancer Epidemiology and Risk (AMBER) consortium. Methods Using immunohistochemistry (IHC), we quantified the expression of ER, PR, HER2, the proliferation marker Ki67, and two basal-like biomarkers, epidermal growth factor receptor (EGFR) and cytokeratin (CK)5/6, in 1381 invasive breast tumors from African American women. RNA-based (prediction analysis of microarray 50 (PAM50)) subtype, available for 574 (42%) cases, was used to optimize classification. Subtype frequency was calculated, and associations between subtype and tumor characteristics were estimated using logistic regression. Results Relative to ER, PR and HER2 from medical records, central IHC staining and the addition of Ki67 or combined tumor grade improved accuracy for classifying PAM50-based luminal subtypes. Few triple negative cases (

Background: Many personal care products include chemicals that might act as endocrine disruptors and thus increase the risk of breast cancer. Objective: We examined the association between usage patterns of beauty, hair, and skin-related personal care products and breast cancer incidence in the Sister Study, a national prospective cohort study (enrollment 2003–2009). Methods: Non-Hispanic black (4,452) and white women (n=42,453) were examined separately using latent class analysis (LCA) to identify groups of individuals with similar patterns of self-reported product use in three categories (beauty, skin, hair). Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between product use and breast cancer incidence. Results: A total of 2,326 women developed breast cancer during follow-up (average follow-up=5.4y). Among black women, none of the latent class hazard ratios was elevated, but there were

Multiple instance (MI) learning with a convolutional neural network enables end-to-end training in the presence of weak image-level labels. We propose a new method for aggregating predictions from smaller regions of the image into an image-level classification by using the quantile function. The quantile function provides a more complete description of the heterogeneity within each image, improving image-level classification. We also adapt image augmentation to the MI framework by randomly selecting cropped regions on which to apply MI aggregation during each epoch of training. This provides a mechanism to study the importance of MI learning. We validate our method on five different classification tasks for breast tumor histology and provide a visualization method for interpreting local image classifications that could lead to future insights into tumor heterogeneity.

Accurate and reproducible classification of tumors is essential for clinical management, cancer surveillance, and studies of pathogenesis and etiology. Tumor classification has historically been based on the primary anatomic site or organ in which the tumor occurs and on its morphologic and histologic phenotype. While pathologic criteria are useful in predicting the average behavior of a group of tumors, histopathology alone cannot accurately predict the prognosis and treatment response of individual cancers. Traditional measures such as tumor stage and grade do not take into account molecular events that influence tumor aggressiveness or changes in the tumor composition during treatment. This chapter provides a primer on approaches that use pathology and molecular biology to classify and subclassify cancers. It describes the features of carcinomas, sarcomas, and malignant neoplasms of the immune system and blood, as well as various high-throughput genomic platforms that characterize the molecular profile of tumors.

Background Cancer-associated fibroblasts (CAFs) support tumour progression and invasion, and they secrete abundant extracellular matrix (ECM) that may shield tumour cells from immune checkpoint or kinase inhibitors. Targeting CAFs using drugs that revert their differentiation, or inhibit their tumour-supportive functions, has been considered as an anti-cancer strategy. Methods We have used human and murine cell culture models, atomic force microscopy (AFM), microarray analyses, CAF/tumour cell spheroid co-cultures and transgenic fibroblast reporter mice to study how targeting HDACs using small molecule inhibitors or siRNAs re-directs CAF differentiation and function in vitro and in vivo. Results From a small molecule screen, we identified Scriptaid, a selective inhibitor of HDACs 1/3/8, as a repressor of TGFβ-mediated CAF differentiation. Scriptaid inhibits ECM secretion, reduces cellular contraction and stiffness, and impairs collective cell invasion in CAF/tumour cell spheroid co-cultures. Scriptaid also reduces CAF abundance and delays tumour growth in vivo. Conclusions Scriptaid is a well-tolerated and effective HDACi that reverses many of the functional and phenotypic properties of CAFs. Impeding or reversing CAF activation/function by altering the cellular epigenetic regulatory machinery could control tumour growth and invasion, and be beneficial in combination with additional therapies that target cancer cells or immune cells directly.

African-American (AA) women have higher breast cancer-specific mortality rates. A higher prevalence of the worse outcome Basal-like breast cancer subtype contributes to this, but AA women also have higher mortality even within the more favorable outcome Luminal A breast cancers. These differences may reflect treatment or health care access issues, inherent biological differences, or both. To identify potential biological differences by race among Luminal A breast cancers, gene expression data from 108 CAU and 57 AA breast tumors were analyzed. Race-associated genes were evaluated for associations with survival. Finally, expression of race- and survival-associated genes was evaluated in normal tissue of AA and CAU women. Six genes (ACOX2, MUC1, CRYBB2, PSPH, SQLE, TYMS) were differentially expressed by race among Luminal A breast cancers and were associated with survival (HR0.8, HR1.25). For all six genes, tumors in AA had higher expression of poor prognosis genes (CRYBB2, PSPH, SQLE, TYMS) and lower expression of good prognosis genes (ACOX2, MUC1). A score based on all six genes predicted survival in a large independent dataset (HR = 1.9 top vs. bottom quartile, 95% CI: 1.4-2.5). For four genes, normal tissue of AA and CAU women showed similar expression (ACOX2, MUC1, SQLE, TYMS); however, the poor outcome-associated genes CRYBB2 and PSPH were more highly expressed in AA versus CAU women's normal tissue. This analysis identified gene expression differences that may contribute to mortality disparities and suggests that among Luminal A breast tumors there are biological differences between AA and CAU patients. Some of these differences (CRYBB2 and PSPH) may exist from the earliest stages of tumor development, or may even precede malignancy.

Laboratory models support an inverse association between anti-Müllerian hormone (AMH) and breast tumor development. Human studies are lacking; one study (N = 105 cases, 204 controls) with prospectively collected serum reported the opposite—an approximate 10-fold increase in breast cancer risk comparing fourth with first quartile AMH levels. We investigated the relation between serum AMH levels and breast cancer risk in a case–control (N = 452 cases, 902 controls) study nested within the prospective Sister Study cohort of 50,884 women. At enrollment, participants were ages 35 to 54, premenopausal, and completed questionnaires on medical and family history, lifestyle factors, and demographics. AMH (ng/mL) was measured by ultrasensitive ELISA in serum collected at enrollment and log-transformed for analysis. Multivariate conditional logistic regression was used to calculate ORs and 95% confidence intervals (CI) to account for matching on age and enrollment year. Mean age at enrollment was 46.8 years with an average 2.9 years from blood draw to breast cancer diagnosis (SD = 1.9). AMH concentrations were below the limit of detection (0.003 ng/mL) for approximately 25% of samples. Compared with samples below the LOD, women with AMH >2.84 ng/mL (90th percentile among controls) had a 2-fold increase in breast cancer odds (OR, 2.25; 95% CI, 1.26–4.02). For each 1-unit increase in lnAMH, overall breast cancer odds increased by 8% (OR, 1.08; 95% CI, 1.02–1.15) and odds of estrogen receptor–positive, invasive disease increased by 15% (OR, 1.15; 95% CI, 1.05–1.25). Our findings demonstrate an overall positive relation between AMH and breast cancer. Cancer Prev Res; 8(6); 528–34. ©2015 AACR.

Gene expression studies indicate that body mass index (BMI) is associated with molecular pathways involved in inflammation, insulin-like growth factor activation, and other carcinogenic processes in breast tissue. The goal of this study was to determine whether BMI is associated with gene methylation in breast tissue and to identify pathways that are commonly methylated in association with high BMI. Epigenome-wide methylation profiles were determined using the Illumina HumanMethylation450 BeadChip array in the non-diseased breast tissue of 81 women undergoing breast surgery between 2009 and 2013 at the University of North Carolina Hospitals. Multivariable, robust linear regression was performed to identify methylation sites associated with BMI at a false discovery rate q value

Cohort mortality studies of underground miners have been used to estimate the number of lung cancer deaths attributable to radon exposure. However, previous studies of the radon–lung cancer association among underground miners may have been subject to healthy worker survivor bias, a type of time-varying confounding by employment status. We examined radon-mortality associations in a study of 4,124 male uranium miners from the Colorado Plateau who were followed from 1950 through 2005. We estimated the time ratio (relative change in median survival time) per 100 working level months (radon exposure averaging 130,000 mega-electron volts of potential α energy per liter of air, per working month) using G-estimation of structural nested models. After controlling for healthy worker survivor bias, the time ratio for lung cancer per 100 working level months was 1.168 (95% confidence interval: 1.152, 1.174). In an unadjusted model, the estimate was 1.102 (95% confidence interval: 1.099, 1.112)—39% lower. Controlling for this bias, we estimated that among 617 lung cancer deaths, 6,071 person-years of life were lost due to occupational radon exposure during follow-up. Our analysis suggests that healthy worker survivor bias in miner cohort studies can be substantial, warranting reexamination of current estimates of radon's estimated impact on lung cancer mortality.

Background: Although obesity is associated with breast cancer incidence and prognosis, the underlying mechanisms are poorly understood. Identification of obesity-associated epigenetic changes in breast tissue may advance mechanistic understanding of breast cancer initiation and progression. The goal of this study, therefore, was to investigate associations between obesity and gene methylation in breast tumors. Methods: Using the Illumina GoldenGate Cancer I Panel, we estimated the association between body mass index (BMI) and gene methylation in 345 breast tumor samples from phase I of the Carolina Breast Cancer Study, a population-based case–control study. Multivariable linear regression was used to identify sites that were differentially methylated by BMI. Stratification by tumor estrogen receptor (ER) status was also conducted. Results: In the majority of the 935 probes analyzed (87%), the average beta value increased with obesity (BMI ≥ 30). Obesity was significantly associated with differential methylation (FDR q < 0.05) in just two gene loci in breast tumor tissue overall and in 21 loci among ER-positive tumors. Obesity was associated with methylation of genes that function in immune response, cell growth, and DNA repair. Conclusions: Obesity is associated with altered methylation overall, and with hypermethylation among ER-positive tumors in particular, suggesting that obesity may influence the methylation of genes with known relevance to cancer. Some of these differences in methylation by obese status may influence levels of gene expression within breast cells. Impact: If our results are validated, obesity-associated methylation sites could serve as targets for prevention and treatment research. Cancer Epidemiol Biomarkers Prev; 24(3); 580–6. ©2015 AACR.

A longer lifetime duration of breastfeeding may decrease the risk of breast cancer by reducing breast inflammation and mitigating inflammatory cytokine expression during postlactational involution. However, little is known about how the inflammatory cytokine profile in human breastmilk changes over time. To study temporal trends in breastmilk cytokine expression, we measured 80 human cytokines in the whey fraction of breastmilk samples from 15 mothers at 1, 4, 8, and 12 weeks postpartum. We used mixed models to identify temporal changes in cytokine expression and investigated parity status (multiparous vs. primiparous) as a potential confounder. Nine cytokines (monocyte chemoattractant protein-1, epithelial-derived neutrophil-activating protein-78, hepatocyte growth factor, insulin-like growth factor-binding protein-1, interleukin-16, interleukin-8, macrophage colony-stimulating factor, osteoprotegerin, and tissue inhibitor of metallopeptidase-2) had significantly decreased expression with increasing breastfeeding duration; all nine have known roles in breast involution, inflammation, and cancer and may serve as biomarkers of changing breast microenvironment. No cytokine significantly increased in level over the study period. Total protein concentration significantly decreased over time (p

Breast cancers detected after a negative breast screening examination and prior to the next screening are referred to as interval cancers. These cancers generally have poor clinical characteristics compared with screen-detected cancers, but associations between interval cancer and genomic cancer characteristics are not well understood. Mammographically screened women diagnosed with primary invasive breast cancer from 1993 to 2013 (n = 370) were identified by linking the Carolina Breast Cancer Study and the Carolina Mammography Registry. Among women with a registry-identified screening mammogram 0 to 24 months before diagnosis, cancers were classified as screen-detected (N = 165) or interval-detected (N = 205). Using logistic regression, we examined the association of mode of detection with cancer characteristics (clinical, IHC, and genomic), overall, and in analyses stratified on mammographic density and race. Interval cancer was associated with large tumors [>2 cm; OR, 2.3; 95% confidence interval (CI), 1.5–3.7], positive nodal status (OR, 1.8; 95% CI, 1.1–2.8), and triple-negative subtype (OR, 2.5; 95% CI, 1.1–5.5). Interval cancers were more likely to have non-Luminal A subtype (OR, 2.9; 95% CI, 1.5–5.7), whereas screen-detected cancers tended to be more indolent (96% had low risk of recurrence genomic scores; 71% were PAM50 Luminal A). When stratifying by mammographic density and race, associations between interval detection and poor prognostic features were similar by race and density status. Strong associations between interval cancers and poor-prognosis genomic features (non-Luminal A subtype and high risk of recurrence score) suggest that aggressive tumor biology is an important contributor to interval cancer rates. Cancer Prev Res; 11(6); 327–36. ©2018 AACR.

Breast carcinogenesis is a multistep process accompanied by widespread molecular and genomic alterations, both in tumor and in surrounding microenvironment. It is known that tumors have altered metabolism, but the metabolic changes in normal or cancer-adjacent, nonmalignant normal tissues and how these changes relate to alterations in gene expression and histological composition are not well understood. Normal or cancer-adjacent normal breast tissues from 99 women of the Normal Breast Study (NBS) were evaluated. Data of metabolomics, gene expression and histological composition was collected by mass spectrometry, whole genome microarray, and digital image, respectively. Unsupervised clustering analysis determined metabolomics-derived subtypes. Their association with genomic and histological features, as well as other breast cancer risk factors, genomic and histological features were evaluated using logistic regression. Unsupervised clustering of metabolites resulted in two main clusters. The metabolite differences between the two clusters suggested enrichment of pathways involved in lipid metabolism, cell growth and proliferation, and migration. Compared with Cluster 1, subjects in Cluster 2 were more likely to be obese (body mass index ≥30 kg/m2, p

Advances in a wide array of scientific technologies have brought data of unprecedented volume and complexity into the oncology research space. These novel big data resources are applied across a variety of contexts-from health services research using data from insurance claims, cancer registries, and electronic health records, to deeper and broader genomic characterizations of disease. Several forms of big data show promise for improving our understanding of racial disparities in breast cancer, and for powering more intelligent and far-reaching interventions to close the racial gap in breast cancer survival. In this article we introduce several major types of big data used in breast cancer disparities research, highlight important findings to date, and discuss how big data may transform breast cancer disparities research in ways that lead to meaningful, lifesaving changes in breast cancer screening and treatment. We also discuss key challenges that may hinder progress in using big data for cancer disparities research and quality improvement.

Background: African American breast cancer patients have lower frequency of hormone receptor-positive (HR+)/human epidermal growth factor receptor 2 (HER2)-negative disease and higher subtype-specific mortality. Racial differences in molecular subtype within clinically defined subgroups are not well understood.Methods: Using data and biospecimens from the population-based Carolina Breast Cancer Study (CBCS) Phase 3 (2008-2013), we classified 980 invasive breast cancers using RNA expression-based PAM50 subtype and recurrence (ROR) score that reflects proliferation and tumor size. Molecular subtypes (Luminal A, Luminal B, HER2-enriched, and Basal-like) and ROR scores (high vs low/medium) were compared by race (blacks vs whites) and age (≤50 years vs > 50 years) using chi-square tests and analysis of variance tests.Results: Black women of all ages had a statistically significantly lower frequency of Luminal A breast cancer (25.4% and 33.6% in blacks vs 42.8% and 52.1% in whites; younger and older, respectively). All other subtype frequencies were higher in black women (case-only odds ratio [OR] = 3.11, 95% confidence interval [CI] = 2.22 to 4.37, for Basal-like; OR = 1.45, 95% CI = 1.02 to 2.06, for Luminal B; OR = 2.04, 95% CI = 1.33 to 3.13, for HER2-enriched). Among clinically HR+/HER2- cases, Luminal A subtype was less common and ROR scores were statistically significantly higher among black women.Conclusions: Multigene assays highlight racial disparities in tumor subtype distribution that persist even in clinically defined subgroups. Differences in tumor biology (eg, HER2-enriched status) may be targetable to reduce disparities among clinically ER+/HER2- cases.