Sherman, ME

Abstract Stromal tumor-infiltrating lymphocytes (sTILs) are often prominent in HER2-enriched and triple negative breast cancers and predict a favorable prognosis for these subtypes. Clinical and epidemiological determinants of sTILs have not been defined in large cohorts. Accordingly, we analyzed these associations for 702 eligible, postmenopausal invasive breast cancer cases from the Cancer Prevention Study (CPS)-II Nutrition cohort. CPS-II included 97,786 women who completed baseline and follow-up surveys since 1992. Women with self-reported breast cancer diagnoses were consented for medical record and tumor tissue retrieval. We analyzed pre-diagnostic data from the survey prior to diagnosis on personal history of benign breast disease (BBD), menopausal hormone use, alcohol intake, cigarette smoking status, waist circumference, body mass index, adult weight gain, nonsteroidal anti-inflammatory drugs, and physical activity. One pathologist (TG) evaluated sTILs using whole slide images of H&E stained sections according to recommendations by the International TILs Working Group 2014. sTIL levels were dichotomized: none/minimal (0-10%) and moderate/high (>10%). We compared the sTIL levels by clinical and epidemiologic risk factors using chi-square statistics. Odds ratio (ORs) and 95% confidence intervals (CIs) for the associations of clinical and epidemiologic risk factors with sTILs were estimated with multivariable logistic regression. Mean age at diagnosis was 71.9 years; 44% of cancers were moderate grade, 74% were localized staged and 88% were luminal-like. Cancers with high/moderate sTIL levels (n=614), compared to none/minimal (n=88), were more likely to be high grade (54% vs. 20%; p-value <0.001), node-positive (41% vs. 22%; p-value <0.001), and non-luminal (36% vs. 8%; p-value <0.001). In a model mutually-adjusted for age at diagnosis and clinical factors, all clinical factors were associated with moderate/high sTIL levels: node-positive (OR=2.15, 95% CI 1.28 – 3.58), high grade (OR=3.98, 95% CI 1.88 – 9.06), and non-luminal subtype (OR=3.65, 95% CI 2.00 – 6.59). Age at diagnosis was not associated with sTIL levels (per year: OR=1.01, 95% CI 0.97 – 1.05). Women with BBD were less likely to have moderate/high sTIL levels than minimal/none sTIL levels (38% vs. 54%; age-adjusted OR=0.50, 95% CI 0.31 – 0.79). Ever smokers also were less likely to have moderate/high sTIL levels (38% vs. 49%) with an OR=0.61 (95% 0.38 – 0.97). Other risk factors were not significantly associated with sTIL levels. In this large epidemiologic cohort, non-luminal cancers had more sTILs than luminal cancers. Women with a personal history of BBD and ever cigarette smokers had significant lower levels of sTILs. Our study is among the first to examine pre-diagnostic risk factors in relation to sTILs and provides the impetus for larger, population-based studies with phenotypic characterization of immune cells. Citation Format: Gaudet MM, Mellow MM, Puvanesarajah S, Gapstur SM, Sherman ME, Gansler T. Associations of epidemiologic and clinical features with intensity of immune infiltrates in postmenopausal breast cancer cases from the cancer prevention study-II cohort [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-08-02.

Abstract Introduction: Identifying biomarkers of breast cancer risk among young women would have value in developing effective screening and prevention strategies at early ages. We have proposed that DNA methylation analysis of breast milk may provide breast cancer risk information among young women, and could possibly provide etiologic clues related to the higher rates of early onset cancers among African American as compared with White women in the US. Objective: The purpose of this project was to identify associations between genome-wide DNA methylation levels in breast milk and race adjusted for other breast cancer risk factors. Study Population: Cancer-free, lactating U.S. Black (n=57) and White (n=82) women, ages 19 to 44, provided frozen breast milk samples, as well as demographic, behavioral, and reproductive data, to the Breastmilk Laboratory at University of Massachusetts Amherst. Women were uniparous and did not have a personal history of breast cancer at the time of milk donation. Methods: DNA was extracted from breast milk samples using the phenol-chloroform method. Genome-wide methylation analysis was performed on breast milk samples using the Infinium HumanMethylation450 BeadChip. Probes with 50% or more missing data, cross-reactive probes, as well as probes with minor allelic frequency greater than 0.05 in European- or African-Americans were removed, leaving 379,042 CpG sites for analysis. Multivariate generalized linear regression models were used to examine associations between race and other breast cancer risk factors and methylation beta values, adjusting for potential confounding factors. P-values less than 1E-7 were considered statistically significant. Results: Black women in this study were more likely to be never smokers, to not have used over-the-counter pain medication in the past week, and to breastfeed longer. After adjustment by age, BMI, smoking status, and batch number, race was significantly associated with differential methylation at 1143 CpG sites, including 1024 at which Black women demonstrated increased methylation levels. Additionally, breastfeeding duration was associated with 269 CpG sites, with 268 showing a significant inverse relationship with methylation. Methylation sites significantly associated with Black race and lactation duration were located within tumor suppressor and promoter genes as well as in genes implicated in obesity and diabetes. Conclusion: This preliminarily analysis of DNA methylation in breast milk suggests that Black women have increased methylation and longer breastfeeding is associated with reduced methylation. Further research to understand how etiologic factors related to breast cancer may alter DNA methylation patterns in normal breast may lead to improved understanding of breast cancer risk at a young age and potentially causes of racial disparities in breast cancer incidence between White and Black women. Citation Format: Davis Lynn BC, Bodelon C, Pfeiffer RM, Yang HP, Yang H, Lee M, Laird PW, Campan M, Weisenberger DJ, Murphy J, Sherman ME, Browne EP, Anderton DL, Arcaro KF, Gierach GL. Differences in genome-wide DNA methylation levels in breast milk by race and lactation duration [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-10-07.