Regular screening mammography before the diagnosis of breast cancer reduces black:white breast cancer differences and modifies negative biological prognostic factors
Black women present with later stage breast cancers compared to white women, and their cancers are more likely to be larger, receptor negative, and undifferentiated. This study evaluated black:white differences in the stage and biology of breast cancer among women who had a screening mammogram at one of two Chicago academic medical centers within two years of the breast cancer diagnosis (regularly screened) and compared them to the black:white differences in the stage and biology of breast cancer in women who had not received mammographic screening within two years of a breast cancer diagnosis (irregularly screened.) There were no significant black:white differences in the proportion of early breast cancers (black = 74 %; white = 69 %, p = NS) in the regularly screened population or in the irregularly screened group (black = 60 %; white = 68 %, p = NS.) The regularly screened population received significantly more mammograms (58 % ≥4 mammograms) compared to the irregularly screened population (41 % ≥4 mammograms.) Black women in the regularly screened population were less likely than irregularly screened black women to have estrogen negative breast cancers (26 vs. 36 %, p < .05), progesterone negative breast cancers (35 vs. 46 %, p < .05), and poorly differentiated breast cancers (39 vs. 53 %, p < .05.) White women in the irregularly screened population also had worse prognostic factors than white women in the regularly screened population, though these were not statistically significant. Regular mammographic screening can contribute to the narrowing of black:white differences in presentation of breast cancer.