Abstract P2-13-02: Risk Factors for high risk breast density patterns in Hispanic/Latinas living in the Northeast, US

Introduction: Breast densities are the non-fat (epithelial and stromal) breast tissue observable on screening mammograms. Known to be associated with a 4 to 6 fold increase in breast cancer risk, dense breast patterns complicate the reading of screening mammograms resulting in lowered sensitivity. Little is currently known about the prevalence and/or predictors of breast density in Hispanic/Latino women living in the Northeast, US. Objective: The goal of this prospective study is to identify risk factors for high risk breast density patterns among a large cohort of Hispanic/Latino women with ancestral ties primarily to the Eastern Caribbean (Puerto Rico and the Dominican Republic) as well as Central and South America. Because the hormonal milieu is somewhat different in Hispanic/Latinas compared with White women, and likely also differs from that of Hispanic/Latinas living in other parts of the US, we explored the role of reproductive and physiological factors in high risk breast density patterns. Methods: We analyzed breast density predictors in an established cohort of 1,600 Hispanic/Latino women recruited from primary care clinics in 4 cities with the largest enclaves of Hispanic/Latinos in Connecticut. Hour-long telephone interviews provided baseline data on biological, medical care, and sociodemographic factors. We retrieved radiology records on 1570 (98.7%) consenting women. For this analysis, we report predictors of breast density among the 1,040 (65.4%) women who received at least one screening mammogram during 2 to 4 years of follow-up. Breast density classification was based on radiologist assigned BI-RADS classification. Associations between predictors and high risk breast density patterns were examined using chi square tests. Multivariate analyses were conducted using logistic regression; odds ratios (OR) and 95% confidence intervals (CI) are reported. Results: Of the 1,040 women who received at least one screening mammogram during the follow-up period, 280 (27%) women were identified as having high risk dense breasts (extremely or heterogeneously dense, i.e., greater than 50% of the breast composed of fibroglandular densities), while 760 women (73%) were classified as having nondense breasts (fatty or scattered fibroglandular densities), suggesting a lower prevalence of high risk breast density patterns in this population. In multivariate analysis, breast density predictors were similar to those reported for the general population (mostly White) women, and are similar to known risk factors for breast cancer. However, we found that Hispanic/Latinas with diabetes to be at significantly reduced odds of high risk breast density patterns. There was also evidence that the relationship between age at menarche and density was modified by BMI, with early age at menarche a risk factor among normal and underweight women only. Conclusion: Our findings suggest that Hispanic/Latino women may differ in breast density prevalence relative to the general population. However, we observed a protective effect of diabetes and a potential interaction between age at menarche and BMI. This investigation enhances our understanding of breast density in a subset of the Hispanic/Latino population and provides the basis for further research. Citation Format: Jones BA, Claye E, Philpotts L, Hooley R, Silber A, Epstein L. Risk Factors for high risk breast density patterns in Hispanic/Latinas living in the Northeast, US [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-13-02.