Racial differences in clinical progression among Medicare recipients after treatment for localized prostate cancer (United States).

OBJECTIVE: Prostate cancer recurrence impacts patient quality of life and risk of prostate-cancer specific death following definitive treatment. We investigate differences in disease-free survival among white, black, Hispanic, and Asian patients in a large, population-based database.

METHODS: Merged Surveillance, Epidemiology, and End Results Program (SEER) and Medicare files provided data on 23,353 white patients, 2,814 black patients, 480 Hispanic patients, and 566 Asian patients diagnosed at age 65-84 years with clinically localized prostate cancer between 1986 and 1996 in five SEER sites. Patients were followed through 1998. Racial differences in disease-free survival were assessed using Kaplan-Meier survival curves and Cox regression models.

RESULTS: The 75th percentile disease-free survival time for black patients was 13 months less than that for white patients (95% confidence interval [CI]: 6.2-19.8 months), 29.7 months less than that for Hispanic patients (95% CI: 4.4-55.0 months), and 39.1 months less than that for Asian patients (95% CI: 12.1-66.1 months). In multivariate analysis, black race predicted shorter disease-free survival among surgery patients, but not among radiation patients.

CONCLUSIONS: Black patients experienced shorter disease-free survival compared to white, Hispanic, and Asian patients, and the disease-free survival of white, Hispanic, and Asian patients were not statistically different. Earlier recurrence of prostate cancer may help explain black patients' increased risk of mortality from prostate cancer.