Abstract IA29: Race, ethnicity, and outcomes in breast cancer

Abstract

Abstract The racial divide in breast cancer outcomes is well known. Breast cancer is the most common cause of cancer in women in the United States, and the second leading cause of cancer death.1 Black race is associated with a worse prognosis in operable breast cancer2 and in other hormone dependent cancers such as uterine and prostate cancer, but generally not other cancer types.3,4 Black women are more likely to present with advanced stage disease5, have triple negative breast cancer (TNBC), exhibit greater non-adherence and poorer tolerance to chemotherapy6 and endocrine therapy7, and have more comorbidities8 and experience more disparities in care.9-11 Black race has also been associated with worse outcome in male breast cancer.12 Although breast cancer incidence and mortality have declined by about 35% in the United States since 1990, mortality rates have declined less in black women, contributing to a widening of the racial gap which has contributed to about a 35% higher mortality rate for black women compared with others.13 However, a widening racial gap has also been observed for women in the U.S. Department of Defense healthcare system, suggesting that factors other than disparities in care may be playing a role. 14 With regard to ethnicity, Hispanic women also exhibit higher rates of TNBC, but otherwise experience similar outcomes as non-Hispanic women. There is emerging evidence that differences in outcomes may be due in part due to factors other than disparities in care. In this review, we explore some of the biological factors that may be contributing to the racial divide in breast cancer.