Percent Free Prostate Specific Antigen Does Not Enhance the Specificity of Total Prostate Specific Antigen for the Detection of Prostate Cancer in Korean Men 50 to 65 Years Old: A Prospective Multicenter Study

Abstract

We investigated the usefulness of percent free prostate specific antigen for detecting prostate cancer in Korean men. A total of 1,528 men with a palpably benign prostate gland and prostate specific antigen 4.0 to 10.0 ng/ml underwent prostate biopsy at 25 hospitals in Korea. Patients were categorized by age into young and old groups, and variables were analyzed in terms of the ability to predict prostate cancer. The 1,528 enrolled patients consisted of 256 (17%) with a positive biopsy and 1,272 with a negative biopsy. Mean percent free prostate specific antigen was significantly different in those with prostate cancer vs benign prostatic disease (p = 0.018). The AUC for percent free and total prostate specific antigen in all patients was 0.57 and 0.53, respectively (p = 0.136). In relation to age groups percent free prostate specific antigen was significantly more predictive of cancer than total prostate specific antigen in the old group but it did not show better sensitivity than total prostate specific antigen in the young group. The AUC for percent free and total prostate specific antigen was 0.55 and 0.55 in the young group (p = 0.468), and 0.65 and 0.53, respectively, in the old group (p <0.001). Our study revealed racial differences in the relationship between percent free prostate specific antigen and cancer detection in men with prostate specific antigen 4.0 to 10.0 ng/ml. Percent free prostate specific antigen provided no added diagnostic benefit vs total prostate specific antigen in Korean men 50 to 65 years old with a palpably benign prostate gland and prostate specific antigen 4.0 to 10.0 ng/ml.