Sherman, Mark E.

Abstract Background: Women with benign breast disease (BBD) experience an increased risk of breast cancer (BC). Histologic classification of BBD, as non-proliferative disease (NP), proliferative disease without atypia (PDWA) or atypical hyperplasia (AH), stratifies groups of patients into progressively higher categories of BC risk. However, this classification does not comprehensively assess the proliferative state of the epithelium throughout the biopsy. In addition, while AH is considered the most high-risk class of BBD, it is not always a highly proliferative lesion; atypical ductal lesions may reflect focal cytologic and architectural changes. We evaluated the association of an alternative classification of BBD severity and BC risk based on subjective grading of: 1) the maximal degree of epithelial proliferation and 2) multifocality of epithelial proliferation. Methods: Pathologists reviewed biopsies from participants aged 18 to 85 years in the Mayo BBD cohort (2002-2013), masked to BC outcomes, ascertained via questionnaires, tumor registry data and medical record review. Biopsies were classified as NP, PDWA or AH and semi-quantitatively scored for: 1) maximal degree of epithelial proliferation within a focus (DP) (0-3; none to severe) and 2) multifocality of proliferation (MP) (0-3; none to multiple foci). DP and MP scores were also summed to give a DP+MP score (0-6). Associations of DP and MP with BC risk were examined using Cox proportional hazards regression analyses, adjusting for age at BBD biopsy. Women were followed from date of initial biopsy to date of BC, death or last follow-up. Results: Of the 1529 assessable biopsies, 544 (35.6%) were classified as NP, 708 (46.3%) as PDWA and 277 (18.1%) as AH. Both DP and MP scores had significant positive correlation with increasing BBD severity (DP: r=0.51, p< 0.001; MP: r=0.52, p< 0.001). Mean (SD) DP scores were 0.6 (0.6) for NP, 1.6 (0.9) for PDWA, and 1.8 (0.7) for AH (ANOVA p<0.001). Mean (SD) for MP scores were 0.6 (0.6) for NP, 1.4 (0.8) for PDWA, and 1.8 (0.8) for AH (ANOVA p<0.001). Mean (SD) for DP+MP scores were 1.2 (1.2) for NP, 2.9 (1.5) for PDWA, and 3.6 (1.2) for AH (ANOVA p<0.001). With median follow-up of 8.8 years for controls and 5.3 years for cases, 10.6% of the women in the cohort developed BC. Compared to those with DP scores of 0, women with DP scores of 3 had significantly increased BC risk (HR 1.42, 95% CI: 1.16, 1.74, p=0.003). MP was associated with a non-significant increase in BC risk for scores of 3 versus 0 (HR: 1.20, 95% CI: 0.97,1.49, p=0.11). DP+MP scores of 6 conferred the highest BC risk (HR (score 6 vs. 0): 1.62, 95% CI 1.18,2.21, p=0.02). Results did not substantively differ after adjusting for BBD severity as NP, PDWA or AH. Conclusions: In this preliminary analysis within the Mayo BBD cohort, both proliferative degree (DP) and multifocality (MP) scores were correlated with histologic severity of BBD. DP and DP+MP scores were each associated with increased BC risk. We conclude that improved characterization of epithelial proliferation in BBD biopsies may enable refined prediction of individual BC risk. Citation Format: Jodi M Carter, Matthew R Jensen, Robert A Vierkant, Stacey J Winham, Tanya L Hoskin, Marlene Frost, Karthik Ghosh, Derek C Radisky, Amy C Degnim, Mark E Sherman. Epithelial proliferation score as an independent breast cancer risk predictor in benign breast disease [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 PD10-10.

Abstract 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.

Abstract 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.

Abstract Background: Tamoxifen therapy has been shown to have greater therapeutic benefit among women whose breast density declines subsequent to treatment than among women whose density does not decline. Although limited data suggests that endocrine symptoms after tamoxifen initiation may be associated with improved breast cancer outcomes, it is unknown whether these symptoms are associated with reductions in breast density. We therefore evaluated endocrine symptoms and change in breast density in a 12-month longitudinal study of women undergoing tamoxifen therapy for clinical indications. Methods: Cohort members (N=74) were aged 30-74 years in the Ultrasound Study of Tamoxifen at Karmanos Cancer Institute and Henry Ford Health Systems (Detroit, MI). Endocrine symptoms and breast density were both assessed prior to tamoxifen initiation (T0) and at 1-3 months (T1), 4-6 months (T2), and approximately 12 months (T3) post-tamoxifen initiation. Treatment-associated endocrine symptoms included treatment-emergent or increasing vasomotor and/or joint symptoms. Endocrine symptom severity was also assessed with a Likert scale for symptom frequency and categorized as no symptoms (score=0), low/moderate symptoms (score=1-5), and high symptoms (score=6+). Sound speed (m/s), a surrogate of volumetric breast density, was measured with whole breast ultrasound tomography. Change in breast density was calculated as density at T1-T3 minus density at T0. We used multivariable linear regression to estimate mean change in density by endocrine symptoms adjusting for age, race, menopausal status, body mass index, and baseline sound speed. Generalized estimating equations were used to account for within-subject correlations over time. Results: Women with treatment-associated endocrine symptoms had an overall greater mean reduction in breast density compared with women without symptoms (mean change [95% CI]: -1.97 m/s [-3.80, -0.13]; -0.27 m/s [- 3.50, 2.95], respectively; p=0.22). Longitudinal trends in breast density significantly differed for women with versus without treatment-associated endocrine symptoms (p-interaction=0.02). Significant declines in breast density over time were observed among women with treatment-associated endocrine symptoms (p-trend=0.005), but not among women without symptoms (p-trend=0.16). Similar trends in breast density decline were observed among women with higher symptom severity (p-trends for no symptoms=0.53; low/moderate symptoms=0.04; high symptoms=0.008). Conclusions: These findings suggest that treatment-associated endocrine symptoms may be associated with a significant decline in breast density after tamoxifen initiation. Further studies are needed to assess whether these observations can predict clinical outcome, and if confirmed, both treatment-associated endocrine symptoms and observed reductions in breast density may be useful for patients and providers to improve adherence. Citation Format: Cody Ramin, Ruth Pfeiffer, Shaoqi Fan, Maeve Mullooly, Roni T. Falk, Mark A. Sak, Michael S. Simon, David H. Gorski, Haythem Ali, Peter Littrup, Nebojsa Duric, Mark E. Sherman, Gretchen L. Gierach. Treatment-associated endocrine symptoms and change in ultrasound tomography measures of breast density after tamoxifen therapy [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 5805.

Abstract Background: Parity reduces risk of late onset breast cancer (BC), but childbirth is associated with a transient rise in BC risk. In a prior analysis of normal breast tissues donated for research to the Komen Tissue Bank (KTB), we reported that numbers of lobules (the primary structures from which BCs arise) are increased among parous versus nulliparous women. To further define the histological features that may be related to the transient rise in post-partum BC risk, we performed an expanded histologic review of 757 breast tissues donated to the KTB by women ≤45 years of age and compared lobule number, acinar count per lobule, and abundance of immune cells, and specifically plasma cells, between nulliparous and parous women. Methods: We assessed digital scans of H&E stained tissue sections of KTB tissues for total number of lobules, and evaluated acini / lobule (ordinal categories) and lobule span (um) for ≤10 lobules per section. Masked to epidemiologic data, we subjectively assessed images including ≥5 lobules for the presence of benign breast disease (BBD), ≥3 plasma cells per section and increased immune cells in lobules. We compared parous women according to time since last birth (≤5 years or >5 years) to nulliparas (referent) using age-adjusted regression models appropriate for data type (count, continuous, ordinal, or categorical). Results: Compared to nulliparous women, parous women ≤5 years of a birth had a 1.83-fold increase in lobule counts (95% confidence interval [CI]: 1.47-2.28, P<0.001), increased plasma cells in lobules (OR=1.86; 95% CI: 1.08-3.18, P<0.025), and subjectively, increased immune cells in lobules (OR=2.46, 95% CI: 1.39-4.36, P<0.002). Comparisons of parous women ≥5 years post-partum to nulliparas revealed a 1.83-fold increase in numbers of lobules (95% CI: 1.42-2.36, P<0.001); however, lobule span in parous women was 0.89 times that of nulliparous women (95% CI: 0.80-0.99, P=0.037) and other features assessed did not show statistically significant differences. Conclusion: Histologically, normal breast tissues reveal persistently increased lobule counts and increased plasma cells and inflammation for ≤5 years post-partum compared with nulliparous women, although other lobular features decrease between ≤5 and >5 years after a birth. Future molecular studies will define how these changes in the epithelium and microenvironment during the post-partum period may inform mechanisms that mediate the transient increase in BC risk after childbirth and the reduction in BC risk that occurs later in life. Citation Format: Joshua Ogony, DereK C. Radisky, Amy C. Degnim, Marlene Frost, Tanya L. Hoskin, Michael G. Heckman, Launia J. White, Mark E. Sherman. Analysis of post-partum breast tissue to understand early onset breast cancer [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 4635.

Abstract Introduction Elevated mammographic density (MD) is a strong and independent risk factor for breast cancer, though underlying mechanisms are unclear. Prior studies have suggested that increased cumulative exposure to sex-steroid hormones and growth factors may impact both MD and MD-related breast cancer risk; however, most studies have only evaluated individual hormones. In this study, we simultaneously explored the relationship between 29 circulating hormones and growth factors with MD among postmenopausal women undergoing diagnostic breast biopsy. Methods We used data from 89 postmenopausal women, aged 44-65, who had complete measurements of 29 serum hormones from a single pre-biopsy blood draw (i.e., sex-steroid hormones: 15 estrogen/estrogen metabolites, 7 progesterone/progesterone metabolites; and non-sex hormones: insulin-like growth factor I and binding proteins (IGFBPs) 2-7). Volumetric MD (% fibroglandular volume) was assessed in pre-biopsy digital mammograms using single X-ray absorptiometry. Sufficient dimension reduction methods were used to compute a composite marker score that accommodates correlations among hormones and their relationship to MD. Backward elimination was applied to select log-transformed hormones contributing to the score at α=0.05; multivariable linear regression was used to further examine associations between selected hormones and MD within a single model, adjusting for age and BMI. Results Pearson correlations between hormones were moderate-to-strong. Dimension reduction methods identified 6 hormones as associated with MD (p<0.05): estradiol, 2-hydroxyestradiol, 2-methoxyestrone, 16-ketoestradiol, IGFBP-2, and 17α-hydroxyprogesterone, in models that considered MD as either continuous or dichotomous (>median vs. ≤median); BMI was consistently identified as the most significant predictor of MD (P <0.0001). In a multivariable linear regression model that included these 6 hormones, in addition to age and BMI, higher levels of 2-methoxyestrone, IGFBP-2, and 17α-hydroxyprogesterone were significantly associated with increased MD, whereas higher levels of age and BMI were significantly associated with lower MD. Conclusions We identified 6 out of 29 correlated hormones that were significantly associated with MD among postmenopausal women. For several, the directions of their associations with MD were comparable to those observed in prior studies that have separately evaluated these hormones in relation to breast cancer risk. We plan to further explore how circulating hormones concurrently affect MD in premenopausal women, accounting for menstrual cycle phase. Incorporation of dimension reduction methods in studies of multiple correlated hormones can help uncover new etiologic insights into the role of hormones and growth factors in MD and breast carcinogenesis and inform strategies for prevention. Citation Format: Shaoqi Fan, Ruth M. Pfeiffer, Manila Hada, Roni T. Falk, Maeve Mullooly, Hannah Oh, Berta Geller, Pamela Vacek, Donald Weave, John Shepherd, Jeff Wang, Sally Herschorn, Louise A. Brinton, Xia Xu, Mark E. Sherman, Britton Trabert, Gretchen L. Gierach. Associations of circulating hormones with mammographic density in postmenopausal women referred to diagnostic breast biopsy [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 3488.

Abstract Background: Biopsy diagnosis of benign breast disease (BBD) based on the most severe lesion in a sample predicts future breast cancer risk and has implications for screening and management. Lobules are the functional unit of the breast and the structures from which BBD arises. We developed and preliminarily validated an automated computational pathology algorithm to discriminate normal from BBD breast lobules as a step toward automated comprehensive characterization of benign biopsies. Methods: 152 BBD biopsies (27 training, 125 validation) from the Mayo Clinic were examined using scanned digital images of H&E stained sections. For each image, a pathologist annotated up to 10 representative lobules as normal or BBD using standard pathology criteria. A deep learning algorithm to quantify lobular features was developed using 129 lobules from 27 subjects. Nine features were identified that discriminate normal vs BBD lobules, expressing lobule size, acini size and number, acinar lumen size, proportion of lobular stroma, and capillaries. Here, we validate their performance to discriminate normal vs BBD lobules in a set of 1250 lobules from 125 subjects using area under the ROC curve (AUC) analysis. Random forest analysis was used for multivariable modeling; model performance was assessed with a tenfold cross-validation approach. Results: Median subject age was 52 years. Among the 125 validation subjects, BBD findings were nonproliferative in 39%, proliferative in 45%, and atypical hyperplasia in 16%. Sections included 552 (44%) normal lobules and 698 BBD (56%) lobules, with representation of both lobule types on each section. In univariate analyses, four individual features showed good discrimination between normal vs. BBD lobules, yielding the following AUCs: lobule size= 0.74, mean acini size= 0.75, epithelial area= 0.75, and number of acini with large lumens= 0.76. Lobule size and epithelial area were highly correlated (Spearman rank correlation r = 0.95), but both of these features showed lower correlation with mean acini size and number of acini with large lumens (each r < 0.5). With random forest modeling, number of acini with large lumens was the strongest discriminating feature, followed by mean acini size, lobule size, and epithelial area. With ten-fold cross validation of the multivariable random forest model, the overall AUC was 0.82 (95% CI: 0.79-0.85). Conclusion: Our validation showed that automated quantitative computational pathology assessment of breast lobules can discriminate normal versus BBD on a per lobule basis. This finding supports the feasibility of developing automated algorithms to classify every lesion in breast biopsies, expanding beyond visual assessment. Further studies using deep learning may reveal novel pathology features for classifying BBD biopsies with the potential to strengthen estimation of breast cancer risk. Citation Format: Amy C. Degnim, Thomas de Bel, Mark E. Sherman, Derek C. Radisky, Stacey J. Winham, Tanya L. Hoskin, Melody L. Stallings Mann, Marlene Frost, Robert A. Vierkant, Brendan T. Broderick, Ethan P. Heinzen, Rushin Brahmbhatt, Muhammad Arshad, Celine M. Vachon, Jodi M. Carter, Lori A. Denison, Daniel W. Visscher, Jeroen van der Laak. Discrimination of benign breast disease from normal lobules using an automated computational pathology algorithm [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 2113.

Abstract Background: Crown-like structures in breast adipose tissue (CLS-B), indicative of proinflammatory conditions, are most frequently observed among obese (body mass index, BMI ≥30 kg/m2) women and may contribute to poor prognosis in this group. African-American (AA) women have disproportionately higher rates of obesity than White women, and at least one prior study suggests the prevalence of CLS-B may be higher among AA women. However, most previous studies have examined CLS-B within affected tissues, which may reflect inflammation in the tumor microenvironment, and few have examined the association between CLS-B and clinical outcomes by race. Methods: We examined the presence of CLS-B detected by CD68 immunohistochemistry in normal adjacent breast tissue from a quadrant uninvolved by tumor obtained via mastectomy among 174 African-American women and 168 White women with stage I—III breast cancer diagnosed at Emory University Hospitals (2007—2012). We also investigated associations between CLS-B and other demographic and lifestyle factors at diagnosis (e.g., BMI, smoking status, age at menarche, parity, lactation, menopausal status, hormone replacement therapy use, and family history of breast cancer). Patients were followed for an average of seven years after diagnosis for recurrence and survival. Multivariable Cox proportional hazards models were used to compute hazard ratios (HR) and 95% confidence intervals (CI) for associations between CLS-B presence and progression-free survival (PFS), controlling for BMI and other potential confounders. Results: Median age at diagnosis for both AA and White women was 54 years, with more than 60% postmenopausal among both groups. AA women were more likely than White women to be obese (52% vs. 24%) and have ER- tumors (30% vs. 12%). Presence of any CLS-B was similar between AA (32%) and White (29%) patients. In multivariable models, we did not find any association between CLS-B and race (HR=1.14, 95% CI: 0.72, 1.82) with the only statistically significant factors being BMI (≥30 vs. 18.5-<25 kg/m2: HR=4.36, 95% CI: 2.17, 8.76) and parity (1+ vs. 0 births: HR=0.43, 95% CI: 0.21, 0.91). Over follow-up, 46 breast cancer recurrences and 52 deaths (23 from breast cancer) occurred. Overall, the presence of CLS-B was not associated with PFS (multivariable HR: 0.97, 95% CI: 0.58, 1.62). When examined by race, there was a difference in the direction of the association between CLS-B and PFS among AA women (HR=1.25, 95% CI: 0.64, 2.46) compared to White women (HR=0.75, 95% CI: 0.33, 1.71), although this difference was not statistically significant (P=0.86). Conclusion: Our results show a strong, positive association between BMI and CLS-B in non-tumor tissue and an inverse association with parity. We did not observe a difference in CLS-B presence by race nor did we find CLS-B to be associated with worse progression-free survival, which is in contrast to previous studies that have examined the presence of CLS-B within specimens in close proximity to the tumor. Citation Format: Aswathy M Cheriyan, Mark E Sherman, Yuan Liu, Keerthi Gogineni, Jiaqi Liu, Jiabei He, Uma Krishnamurti, Ryan Ashiqueali, Jinjing He, Rami Yacoub, Jasmine Miller-Kleinhenz, Lauren E McCullough, Maret L Maliniak. Presence of crown-like structures in breast adipose tissue and clinical outcomes among African-American and White breast cancer patients [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 C074.

AbstractThe etiology of triple-negative breast cancers (TNBC) is poorly understood. As many TNBCs develop prior to the initiation of breast cancer screening or at younger ages when the sensitivity of mammography is comparatively low, understanding the etiology of TNBCs is critical for discovering novel prevention approaches for these tumors. Furthermore, the higher incidence rate of estrogen receptor–negative breast cancers, and specifically, of TNBCs, among young African American women (AAW) versus white women is a source of racial disparities in breast cancer mortality. Whereas immune responses to TNBCs have received considerable attention in relation to prognosis and treatment, the concept that dysregulated immune responses may predispose to the development of TNBCs has received limited attention. We present evidence that dysregulated immune responses are critical in the pathogenesis of TNBCs, based on the molecular biology of the cancers and the mechanisms proposed to mediate TNBC risk factors. Furthermore, proposed risk factors for TNBC, especially childbearing without breastfeeding, high parity, and obesity, are more prevalent among AAW than white women. Limited data suggest genetic differences in immune responses by race, which favor a stronger Thr type 2 (Th2) immune response among AAW than white women. Th2 responses contribute to wound-healing processes, which are implicated in the pathogenesis of TNBCs. Accordingly, we review data on the link between immune responses and TNBC risk and consider whether the prevalence of risk factors that result in dysregulated immunity is higher among AAW than white women.

Abstract Over one million women in the United States receive biopsy diagnoses of benign breast disease (BBD) each year, which confer a 1.5–4.0-fold increase in breast cancer risk. Studies in the general population suggest that nonsteroidal anti-inflammatory agents (NSAID) lower breast cancer risk; however, associations among women with BBD are unknown. We assessed whether NSAID use among women diagnosed with BBD is associated with lower breast cancer risk. Participants included 3,080 women (mean age = 50.3 ± 13.5 years) in the Mayo BBD surgical biopsy cohort diagnosed between January 1, 1992 and December 31, 2001 who completed breast cancer risk factor questionnaires that assessed NSAID use, and whose biopsies underwent detailed pathology review, masked to outcome. Women were followed from date of BBD biopsy to breast cancer diagnosis (main outcome) or censoring (death, prophylactic mastectomy, reduction mammoplasty, lobular carcinoma in situ or last contact). Median follow-up time was 16.4 ± 6.0 years. Incident breast cancer was diagnosed among 312 women over a median follow-up of 9.9 years. Regular non-aspirin NSAID use was associated with lower breast cancer risk [HR = 0.63; 95% confidence interval (CI) = 0.46–0.85; P = 0.002] with trends of lower risk (highest tertiles of use vs. nonuse) for greater number of years used [HR = 0.55; 95% CI = 0.31–0.97; Ptrend = 0.003), days used per month (HR = 0.51; 95% CI = 0.33–0.80; Ptrend = 0.001) and lifetime number of doses taken (HR = 0.53; 95% CI = 0.31–0.89; Ptrend = 0.003). We conclude that nonaspirin NSAID use is associated with statistically significant lower breast cancer risk after a BBD biopsy, including a dose–response effect, suggesting a potential role for NSAIDs in breast cancer prevention among patients with BBD.