DEMOGRAPHIC DIFFERENCES IN PROSTATE-CANCER INCIDENCE AND STAGE - AN EXAMINATION OF POPULATION DIVERSITY IN CALIFORNIA

Introduction: Geographic and racial/ethnic variability in prostate can cer incidence rates and stage distribution ma;ri be partly attributed to differences in screening and ear ly detection. Methods: Using Calif ornia Cancer Registry data we aimed to characterize variability in pro state cancer rates statewide and to examine differences in the stage a t diagnosis of prostate cancer by racial/ethnic group statewide and by census tract per capita income in San Diego County. We calculated ann ual average (1988-1991) age-adjusted incidence rates per 100,000 (AAIR ) of prostate cancer for 49,880 men over age 34 years. Racial/ethnic g roups were compared using incidence rate ratios (IRR) (AAIR localized plus regional stages AAIR distant stage). Results: Statewide, Caucasia ns showed a higher IRR [6.16, 95% confidence interval (CI), 6.00-6.30] than did African Americans (2.34, 95% CI, 1.89-2.89), Hispanics (3.84 , 95% CI; 3,63-4.05), or Asian/others (3.61, 95% CI, 1.80-7.22). Withi n San Diego County, Caucasians living in higher per capita income cens us tracts (greater than or equal to 65th percentile) had a significant ly higher IRR (8.80, 95% CI 7.84-9.89) than did lower-income tracts (5 .68, 95% CI, 5.13-6.30). Conclusion: Findings from the present and sim ilar studies suggest that outcomes research is needed to determine the impact of these demographic differences on prostate cancer mortality and quality of life. This is particularly important given the current controversy regarding the treatment of clinically localized prostate c ancers, increasingly found through early detection, which often involv e difficult choices between aggressive therapies including prostatecto my or watchful waiting.