Background: In order to enhance prostate-specific antigen (PSA) as a predictor of prostate cancer, it is necessary to understand the characteristics of this tumor marker in a population of men without evidence of prostate cancer but who are at risk for developing the condition.
Methods: In an age-stratified population of 328 men with lower urinary tract symptoms (LUTS), we analyzed the distribution of PSA levels as a function of age and prostate volume, and we analyzed the percentage of age-related variance in PSA that can be explained by the age-related variance in prostate volume.
Results: Classifying the 328 cases with LUTS according to four age groups, a correlation was found between PSA and prostate volume, becoming stronger from the younger (correlation coefficient, -0.1265) to the older group (correlation coefficient, 0.6044). Serum PSA variance per milliliter of prostate volume also increased from the younger (not significant, P > 0.1) to the older age decades (7.3% in men age 70 years or over). Moreover, the results of the regression analysis suggest that 10% of the variance in PSA with age can be accounted for by prostate volume in men under age 50 years, reaching 37% in men age 70 years or more.
Conclusions: These data confirm that the serum PSA concentration increases with advancing age in the absence of clinically evident prostatic malignancy. In younger patients with LUTS, serum PSA variance with age seems to be less dependent upon the age-related variance in prostate volume.