Prostate-Specific Antigen Stratification for Predicting Advanced Prostate Cancer Events in Men Approaching Age Limits for Recommended Screening.

Abstract

Purpose: Our goal was to quantify the ability of various PSA values in predicting the likelihood of developing metastatic or fatal prostate cancer in older men.

Materials and methods: We used a random sample of patients in the US Veterans Health Administration to identify 80,706 men who had received PSA testing between ages 70 to 75. Our primary end point was time to development of either metastatic prostate cancer or death from prostate cancer. We used cumulative/dynamic modeling to account for competing events (death from non-prostate cancer causes) in studying both the discriminative ability of PSA as well as for positive predictive value and negative predictive value at 3 time points.

Results: PSA demonstrated time-dependent predictive discrimination, with receiver operating characteristic area under the curve at 5, 10, and 14 years decreasing from 0.83 to 0.77 to 0.73, respectively, but without statistically significant difference when stratified by race. At PSA thresholds between 1 and 8 ng/mL, the positive predictive value of developing advanced prostate cancer was significantly greater in Black than White patients. For instance, at a PSA > 3, at 5, 10, and 14 years, White patients had 2.4%, 2.9%, and 3.7% risk of an event, whereas Black patients had 4.3%, 6.5%, and 8.3% risk.

Conclusions: In men aged 70 to 75 deciding whether to cease PSA testing with borderline-elevated PSA values, the risk of developing metastatic or fatal prostate cancer is quantifiable and relatively low. Risk assessment in this setting must account for the higher incidence of prostate cancer in Black men.