Differences in prognostic factors and survival among White men and Black men with prostate cancer, California, 1995-2004.

The authors conducted a study to determine whether differences in prostate cancer survival between White men and Black men are reduced or eliminated after accounting for differences in prognostic factors. Using population-based statewide cancer registry data, the authors analyzed data from a cohort of 122,375 non-Hispanic White men and Black men from California who were newly diagnosed with prostate cancer between 1995 and 2004 and followed through 2004. Compared with White men, Black men were characterized by younger age at diagnosis, more distant stage, less treatment with surgery or radiation therapy, higher tumor grades, lower neighborhood socioeconomic status, and more recent year of diagnosis. Adjusted only for age, the hazard ratio for prostate cancer death (Blacks vs. Whites) was 1.61 (95% confidence interval (CI): 1.50, 1.72). Additional adjustment for potentially modifiable factors (stage and treatment) eliminated most of the racial difference in survival (adjusted hazard ratio = 1.10, 95% CI: 1.03, 1.18). The racial difference in survival was completely eliminated after further adjustment for other factors (grade, socioeconomic status, and year of diagnosis) (adjusted hazard ratio = 0.99, 95% CI: 0.92, 1.06). Thus, the large difference in prostate cancer survival between White men and Black men was completely explained by known prognostic factors, with potentially modifiable disparities playing the largest role.