Purpose: To investigate the association between energy-related risk factors and breast cancer subtypes in African American women. We hypothesized that African American women with triple negative breast cancer (TNBC), based on being negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2, would be less likely to have energy-related risk factors than women with other breast cancer subtypes (1) estrogen receptor positive (ER+), and (2) estrogen receptor negative (ER-). Methods: African American women ages 25-75 years diagnosed with primary invasive breast cancer in 2009-2014 in Tennessee, South Carolina, and Georgia were eligible for the study. A total of 697 women (premenopausal n=156; postmenopausal n=541) provided information on energy-related risk factors in a telephone interview and consented to review of tumor tissue. Energy-related risk factors were defined as: no physical activity (54%), high meat intake (upper quartile), obese class II/III (32%), and high weight gain since age 18 (upper quartile). Breast cancer subtype was obtained from pathology reports that accompanied tumor tissue. Results: Although not significantly different, premenopausal (odds ratio (OR) 1.34) and postmenopausal (OR 1.26) women with TNBC were more likely to have high meat intake relative to women with ER+ disease. Premenopausal, but not postmenopausal, women with TNBC were also more likely to have high weight gain since age 18. Women with ER- disease were more likely to have high meat intake, be obese class II/III, and have high weight gain than women with ER+ disease which was more pronounced among premenopausal than postmenopausal women. Conclusions: Histologic subtyping is currently being performed on collected tissue to confirm the reported breast cancer subtypes in the pathology reports. The large number of African American women participating in our study can further our understanding of the relationships between energy-related risk factors and breast cancer subtypes in this population.

Citation Format: Mieke Fortune, Steffie-Ann Dujon, Mary K Fadden, Loren Lipworth, Maureen Sanderson. Energy-related risk factors and breast cancer subtypes in African American women [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 C026.