Free PSA and Clinically Significant and Fatal Prostate Cancer in the PLCO Screening Trial
Kendrick Yim, Chaoran Ma, Sigrid Carlsson, Hans Lilja, Lorelei A. Mucci, Kathryn L. Penney, Adam S. Kibel, Scott E. Eggener, Mark A. Preston
Abstract
PURPOSE: We studied whether adding percent free PSA to total PSA improves prediction of clinically significant prostate cancer and fatal prostate cancer. MATERIALS AND METHODS: A total of 6,727 men within the intervention arm of PLCO (Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial) had baseline percent free PSA. Of this cohort, 475 had clinically significant prostate cancer and 98 had fatal prostate cancer. Cumulative incidence and Cox analyses were conducted to evaluate the association between percent free PSA/PSA and clinically significant prostate cancer/fatal prostate cancer. Harrell's C index evaluated predictive ability. Kaplan-Meier analysis assessed survival. RESULTS: < .001) per 1% decrease. Percent free PSA improved prediction of clinically significant prostate cancer and fatal prostate cancer for all race groups. CONCLUSIONS: In a large U.S. screening trial, the addition of percent free PSA to total PSA in men with baseline PSA ≥2 ng/mL improved prediction of clinically significant prostate cancer and fatal prostate cancer. Free PSA should be used to risk-stratify screening and decrease unnecessary prostate biopsies.