Epidemiology of advanced prostate cancer: Overview of known and less explored disparities in prostate cancer prognosis

Abstract

Several studies have investigated potential explanations of the well-known disparate survival of African Americans with prostate cancer compared with white patients in the United States. Using data from the Detroit Surveillance, Epidemiology, and End Results (SEER) registry for the period 1988-1992, Schwartz et al. found that African American men with localized or regional prostate cancer had a 30% lower survival rate than their white counterparts. The corresponding difference in survival rates for those with distant disease was 75%. These disparities in all-cause mortality were explained by socioeconomic status (SES) and treatment, but not by the differences in age and tumor grade. An earlier cohort study combined information from the US Census with the data from the San Francisco Bay Area SEER registry to assess survival among men diagnosed with prostate cancer between 1973 and 1993. The California registry analyses were conducted using 2 end points: death due to prostate cancer and death due to other causes. The data indicated that differences in SES did not explain why African American men die of prostate cancer at a higher rate when compared with white men. By contrast, SES-associated differences appeared to explain almost all of the racial differences in risk of death due to other causes. To further address the contribution of various factors to differences in prostate cancer survival, Taksler et al estimated that choice of treatment and physician explained only approximately 17% of the racial gap in prostate cancer mortality. Socioeconomic factors and comorbidities explained an additional 15% and 4%, respectively, and the remaining disparity was attributable to tumor characteristics (50%) and other, yet unidentified, factors. Powell et al compared prostate tumor characteristics among African American and white men representing 2 groups: those who died of causes other than prostate cancer, but were found to have the disease on autopsy, and those diagnosed with prostate cancer who underwent radical prostatectomy. Autopsy data indicated that pathologic characteristics of subclinical prostate cancer in African American and white men do not differ by race. Radical prostatectomy data, on the contrary, revealed that prostate cancers (measured by adding the volumes of the individual foci) tended to be larger and Gleason grade on average was higher in African American patients.