Abstract B17: Family history of breast and ovarian cancer prevalence and its association with triple-negative subtype in Hispanic women

Background: A family history of breast cancer in a first-degree relative is an established risk factor for breast cancer; however, little is known about the profile of breast and ovarian family history in Hispanic/Latina women. Importance of this relates to recent reports showing a high prevalence of BRCA mutations in Hispanic/Latina women and a pattern of multiple recurrent mutations. In addition, less is known about the association of family history and tumor subtype in this growing ethnic group in the U.S. Methods: Study participants included breast cancer patients of Mexican descent enrolled in the Ella Binational Breast Cancer Study. We first assessed the self-reported breast and ovarian family history profile in 1,150 women. Second, we compared differences in family history of breast and ovarian cancer prevalence between triple negative breast cancer (TNBC) and non-TNBC in 914 patients with available tumor subtype data. Logistic regression was conducted to compare odds of TNBC to non-TNBC according to family history of breast and ovarian cancer. Results: Prevalence of breast cancer family history in a first- and first- or second-degree relative was 13.1% and 24.1%, respectively. A history of breast or ovarian cancer in first-degree relatives was reported in 14.9% of the women. After adjustment for age and country of residence, women with a first-degree relative with breast cancer were more likely to be diagnosed with TNBC compared to non-TNBC (OR=1.98; 95% CI, 1.26-3.11). The odds of TNBC compared to non-TNBC was 1.93 (95% CI, 1.26–2.97) for women with first-degree relatives with breast or ovarian cancer. There was a suggestion of stronger associations between family history and TNBC among women diagnosed at age 50 years for breast cancer history in first-degree (P-interaction=0.14) and first- or second-degree relatives (P-interaction=0.07). Conclusion: Findings suggest that familial cancers are associated with triple negative subtype, possibly related to the prevalence of BRCA mutations in Hispanic women, which are strongly associated with TNBC. Improvement in collection of family history through new tools and instruments targeting English- and Spanish-speaking Hispanic women should be a priority for future research. Identification of a strong family history can ultimately affect treatment plans, screening practices, and prevention options both for patients and their relatives. Citation Format: Maria Elena Martinez, Kristin An