Racial differences in longitudinal changes in serum prostate-specific antigen levels: the Olmsted County Study and the Flint Men's Health Study.

ABSTRACT

OBJECTIVE: To determine the distribution of, and racial differences in, changes in prostate-specific antigen (PSA) from a population-based sample of men. MATERIALS AND METHODS: Data from 2 prospective cohort studies of a random sample of white men, aged 40-79 years in 1990, followed biennially through 2007, and African American men, aged 40-79 years in 1996, followed through 2000, were examined to assess the longitudinal changes in PSA concentrations. Serum PSA levels were determined at each examination for both cohorts and observations after a diagnosis of prostate cancer or treatment of benign prostatic hyperplasia were censored. The observed and estimated annual percentage of change in the serum PSA levels were examined by race. RESULTS: At baseline, the median PSA level in the white men did not differ from the median level observed in the African American men (white men 0.9 ng/mL; African American men 0.9 ng/mL; P = .48). However, African American men had a much more rapid increase in the PSA level over time compared with the white men (median annual percent change in PSA for white men 3.6%/y, African American men 7.9%/y; P <.001). CONCLUSION: These data suggest that African American men have more rapid rates of change in the PSA levels over time. If the difference in the rate of changes between African American and white men is an early indicator of future prostate cancer diagnosis, earlier detection in African American men could help to alleviate the racial disparities in prostate cancer diagnosis and mortality.