Abstract
PURPOSE: The aim of this study was to investigate the cumulative probability of prostate cancer detection according to free/total prostate-specific antigen (PSA) ratio in men with PSA levels of 2.1-10.0 ng/ml and also likelihood of detecting clinically insignificant prostate cancer in population-based screening. METHODS: A total of 1,277 men aged between 55 and 69 years with total PSA (tPSA) levels of 2.1-10.0 ng/ml screened in population screening in Kanazawa city and underwent systematic transrectal ultrasonography-guided prostate biopsy between 2000 and 2011 were enrolled. The cumulative probability of prostate cancer detection in biopsy according to age, serum tPSA, and free-to-total PSA (f/t PSA) ratio was investigated. The clinicopathological features of screening-detected prostate cancer were also investigated. RESULTS: Of the 1,277 subjects in the study population, 320 (25.0 %) were diagnosed with prostate cancer during the observation period. The probabilities of prostate cancer detection at 3 years were 64.5, 41.2, 28.5, and 14.3 % for the men with f/t PSA ratio ≤0.08, 0.09-0.13, 0.14-0.22, and ≥0.23, respectively; the differences in probabilities of prostate cancer detection among men with different f/t PSA ratios were statistically significant. Among 320 patients, 84 (26.3 %) had favorable clinicopathological features that made them suitable for active surveillance. The f/t PSA ratio in unfavorable cancer patients was significantly lower that that in favorable cancer patients. CONCLUSION: The present study demonstrated that the f/t PSA ratio was a strong predictor of future cancer detection and unfavorable cancerous features in prostate biopsy in men with total PSA levels of 2.1-10.0 ng/ml at population screening.