Risk factors for estrogen receptor positive ductal carcinoma in situ of the breast in African American women

Background Compared to U.S. white women, African American women are more likely to die from ductal carcinoma in situ (DCIS). Elucidation of risk factors for DCIS in African American women may provide opportunities for risk reduction. Methods We used data from three epidemiologic studies in the African American Breast Cancer Epidemiology and Risk Consortium to study risk factors for estrogen receptor (ER) positive DCIS (488 cases; 13,830 controls). Results were compared to associations observed for ER+ invasive breast cancer (n = 2,099). Results First degree family history of breast cancer was associated with increased risk of ER+ DCIS [odds ratio (OR): 1.69, 95% confidence interval (CI): 1.31, 2.17]. Oral contraceptive use within the past 10 years (vs. never) was also associated with increased risk (OR: 1.43, 95%CI: 1.03, 1.97), as was late age at first birth (≥25 years vs.
Highlights • Few studies of risk factors for ductal carcinoma in situ (DCIS) have evaluated associations for African American women. • We analyzed data from the African American African American Breast Cancer Epidemiology and Risk (AMBER) Consortium. • Family history of breast cancer, reproductive factors, and anthropometric factors were associated with risk of ER+ DCIS. • In general, risk factor associations for ER+ DCIS were similar to those for ER+ invasive breast cancer. • Our findings support a common etiology and pathogenesis between ER+ DICS and ER+ invasive cancer in African American women.