Racial differences in breast cancer survival in the Detroit Metropolitan area.

African American (AA) women have poorer breast cancer survival compared to Caucasian American (CA) women. The purpose of this analysis was to determine whether socioeconomic status (SES) and treatment differences influence racial differences in breast cancer survival. The study population included 9,321 women (82% CA, 18% AA) diagnosed with local (63%) or regional (37%) stage disease between 1988 and 1992, identified through the Metropolitan Detroit SEER registry. Data on SES were obtained through linkage with the 1990 Census of Population and Housing Summary Tape and cases were geocoded to census block groups. Pathology, treatment and survival data were obtained through SEER. Cox proportional hazards models were used to compare survival for AA versus CA women after adjusting for age, SES, tumor size, number of involved lymph nodes, and treatment. AA women were more likely to live in a geographic area classified as working poor than were CA women (p<0.001). AA women were less likely to have lumpectomy and radiation and more likely to have mastectomy with radiation (p<0.001). After multivariable adjusted analysis, there were no significant racial differences in survival among women with local stage disease, although AA women with regional stage disease had persistent but attenuated poorer survival compared to CA women. After adjusting for known clinical and SES predictors of survival, AA and CA women who are diagnosed with local disease demonstrate similar overall and breast cancer-specific survival, while race continues to have an independent effect among women presenting at a later stage of disease.