Rodney Breau, M.D., a Mayo Clinic urologic oncology fellow discusses new Mayo Clinic research that studied the association between prostate-specific antigen levels and prostate size and found that routine annual evaluation of prostate growth is not necessarily a predictor for the development of prostate cancer. These findings were presented at the North Central Section of the American Urological Association in Scottsdale, Ariz.
ABSTRACT
Introduction: We evaluated the rate of prostate growth and the rate of change in PSA for men in a large population-based cohort.
Methods: In 1990, 616 men between 40 and 79 years of age without prostate disease were randomly selected from Olmsted County, Minnesota. Patients participated in biennial examinations for 14 years which included PSA and transrectal ultrasonographic prostate volume measurements. The ratios of longitudinal change in PSA and prostate volume were compared between groups.
Results: Of 616 men, 58 (9.4%) were diagnosed with prostate cancer. The median PSA velocity in patients with and without a prostate cancer diagnosis was 6.0%/year and 3.3%/year, respectively. In both groups of patients, median prostate volume increase was 2.2% per year. For patients who developed prostate cancer, the rate of PSA increase was 2.5 (IQR:2.0-3.3) times the rate of prostate volume increase, compared to a rate of 1.5 (IQR:0.8-2.2) for those who did not develop prostate cancer (p<0.001).
Conclusions: In a large population based cohort, men who developed prostate cancer had a similar rate of prostate growth but a disproportionate rise in PSA compared to men who did not develop prostate cancer. These results suggest that the disproportionate rise in PSA in men who develop prostate cancer is not due solely to concomitant prostatic enlargement.
