Initial prostate specific antigen 1.5 ng/ml or greater in men 50 years old or younger predicts higher prostate cancer risk.

Purpose: Studies show that initial prostate specific antigen higher than the median in young men predicts a subsequent higher risk of prostate cancer. To our knowledge this relationship has not been studied in patients stratified by race.

Materials And Methods: A cohort of 3,530 black and 6,118 white men 50 years or younger with prostate specific antigen 4 ng/ml or less at the first prostate specific antigen screening was retrieved from the prostate center database at our institution. Patients were divided into groups based on initial prostate specific antigen 0.1 to 0.6, 0.7 to 1.4, 1.5 to 2.4 and 2.5 to 4.0 ng/ml. Univariate and age adjusted multivariate logistic regression was done to estimate the cancer RR in these prostate specific antigen groups. We calculated the prostate cancer rate at subsequent followups.

Results: Median prostate specific antigen in black and white men was 0.7 ng/ml at age 50 years or less. The prostate cancer rate was not significantly different in the groups with prostate specific antigen less than 0.6 and 0.7 to 1.4 ng/ml in black or white men. Black and white men with initial prostate specific antigen in the 1.5 to 2.4 ng/ml range had a 9.3 and 6.7-fold increase in the age adjusted prostate cancer RR, respectively. At up to 9 years of followup initial prostate specific antigen 1.5 ng/ml or greater was associated with gradually increased detection at followup in black and white men.

Conclusions: An initial prostate specific antigen cutoff of 1.5 ng/ml may be better than median prostate specific antigen 0.7 ng/ml to determine the risk of prostate cancer in black and white men 50 years old or younger.