Prostate Specific Antigen Velocity Threshold for Predicting Prostate Cancer in Young Men

Abstract

Longitudinal changes in prostate specific antigen are increasingly used to guide the recommendation for biopsy. Prostate specific antigen velocity 0.75 ng/ml yearly has been proposed to distinguish prostate cancer from benign prostate conditions. However, this threshold might be too high in young men with lower total prostate specific antigen. In a large prostate cancer screening study 6,844 men were 60 years or younger at study entry and prostate specific antigen velocity calculation was possible. Of these men 346 (5%) were subsequently diagnosed with prostate cancer and various prostate specific antigen velocity thresholds were examined for prediction of prostate cancer risk. Multivariate analysis was performed to determine whether prostate specific antigen velocity is an independent predictor of prostate cancer in men younger than 60 years. Median prostate specific antigen velocity was significantly higher in men who were later diagnosed with prostate cancer than in those who were not (0.840 vs 0.094 ng/ml yearly, p<0.0001). On multivariate analysis prostate specific antigen velocity greater than 0.4 ng/ml yearly was more predictive of prostate cancer than age, total prostate specific antigen, family history or race. Multivariate analysis in the subgroup of men with total prostate specific antigen less than 2.5 ng/ml had similar results. Overall a cutoff of 0.4 ng/ml yearly was associated with 67.3% sensitivity, 81.2% specificity, 16% positive predictive value and 98% negative predictive value for prostate cancer detection in young men. The traditional prostate specific antigen velocity threshold of 0.75 ng/ml yearly is too high for men younger than 60 years and it misses 48% of prostate cancers. Young men with prostate specific antigen velocity greater than 0.4 ng/ml yearly are at significantly greater risk for prostate cancer and close followup is warranted.