Prostate-specific antigen velocity (PSAV) risk count improves the specificity of screening for clinically significant prostate cancer

OBJECTIVE To determine whether the prostate-specific antigen velocity (PSAV) risk count (i.e. the number of times PSAV exceeds a specific threshold) could increase the specificity of screening for prostate cancer and potentially life-threatening tumours. PATIENTS AND METHODS From 1989 to 2001, we calculated two serial PSAV measurements in 18 214 prostate cancer screening-study participants, of whom 1125 (6.2%) were diagnosed with prostate cancer. The PSAV risk count was determined as the number of PSAV measurements of > 0.4 ng/mL/year (0, 1, or 2). We used receiver operating characteristic (ROC) and reclassification analyses to examine the ability of PSAV risk count to predict screen-detected and high-grade prostate cancer. RESULTS The PSAV was > 0.4 ng/mL/year twice (risk count 2) in 40% of prostate cancer cases compared with only 4% of those with no cancer (P < 0.001). After adjusting for age and PSA level, a PSAV risk count of 2 was associated with an 8.2-fold increased risk of prostate cancer (95% confidence interval 7.0-9.6, P < 0.001) and 5.4-fold increased risk of Gleason score 8-10 prostate cancer on biopsy. Compared with a model with age and PSA level, the addition of the PSAV risk count significantly improved discrimination (area under the ROC curve 0.625 vs 0.725, P = 0.031) and reclassified individuals for the risk of high-grade prostate cancer (net reclassification, P < 0.001). CONCLUSIONS Sustained rises in PSA indicate a significantly greater risk of prostate cancer, particularly high-grade disease. Compared with men with a risk count of = 1, those with two PSAV measurements of > 0.4 ng/mL/year (risk count 2) had an 8-fold increased risk of prostate cancer and 5.4-fold increased risk of Gleason 8-10 disease on biopsy, adjusting for age and PSA level. Compared to PSA alone, PSAV risk count may be useful in reducing unnecessary biopsies and the diagnosis of low-risk prostate cancer.