Racial differences in prostate-specific antigen levels and prostate-specific antigen densities in patients with prostate cancer

To compare serum prostate-specific antigen (PSA) levels and PSA density (PS AD) among African American (AA), white, and Hispanic men with prostate canc er (PC) seen in an urban, equal-access urology clinic. Between January 1988 and January 1993, 1,105 men were screened for PC at Cook County Hospital i n Chicago, Illinois. A total of 529 men underwent transrectal ultrasound-gu ided prostate gland biopsies for abnormal digital rectal examination, suspe ct transrectal ultrasound, elevated PSA, or any combination of these abnorm alities. PC was found in 246 patients (204 AAs, 22 whites, and 20 Hispanics ). We analyzed the differences in PSA and PSAD among the three racial group s using univariate and multivariate analyses adjusting for race, age, clini cal stage, and grade. AAs have a higher mean serum PSA levels (21.56 ng/ml) than whites (mean PSA of 10.96 ng/ml) and Hispanics (mean PSA of 8.25 ng/m l) (p = 0.04). The mean PSAD also was higher in AAs than in the other two g roups (0.68 versus 0.34 for whites and 0.31 for Hispanics, p = 0.05). On a multivariate analysis, the PC stage and grade were overwhelmingly significa nt, whereas the race and age lost their statistical significance. AAs have higher serum PSA and PSAD than whites or Hispanics in an equal-access healt hcare environment. Race is a significant factor in determining PSA and PSAD on univariate but not on multivariate analysis. Preliminary studies sugges t that these differences are due to sociological, not biologic causes. Thes e findings warrant a large, prospective study to investigate the extent and the causes of the racial differences in PSA and PSAD.