Race, income, and survival from breast cancer at two public hospitals

Background. Some studies have shown that adjustment for socioeconomic status reduces breast cancer survival differences between blacks and whites. The purpose of this study is to evaluate the effect of age, race, stage, treatment, and income status on breast cancer survival among women attending public hospitals in Chicago, Illinois. Methods. Hospital Cancer Registry data on 887 black women and 265 white women with breast cancer onset between 1973–1985 were analyzed using Cox regression and Kaplan–Meier techniques. The purpose was to examine the effect of age, race, stage, treatment, and income on breast cancer survival. Results. Black women with breast cancer were younger and poorer than white women with breast cancer. There were no significant differences between blacks and whites with regard to stage, estrogen receptor status, or type of treatment. Black women had lower 5‐year breast cancer survival rates compared to white women (50.2% versus 60.2%; P = 0.05), and survival was lower when adjusted for stage and age. However, when adjusted for income in addition to stage and age, the effect of race on survival was reduced (from relative risk = 1.26; 95% confidence interval = 1.02, 1.57 to relative risk = 1.17; 95% confidence interval = 0.95, 1.38). Conclusions. Income influences breast cancer survival differences between blacks and whites in this population.