Prostate-Specific Antigen Velocity Risk Count Assessment: A New Concept for Detection of Life-Threatening Prostate Cancer During Window of Curability

Objectives: To determine whether the number of times the prostate-specific antigen (PSA) velocity (PSAV) exceeds a threshold (PSAV risk count) is predictive of high-risk prostate cancer. Methods: The PSAV was determined in 717 men (606 without prostate cancer; 32 with high-risk prostate cancer defined as death from cancer, PSA level of 20 ng/mL or more, or a Gleason score of 8 or more; and 79 with prostate cancer who were alive or dead of another cause). Multiple PSAVs determined from three repeated measures from each subject during 10 to 20 years were used to determine the risk count by summing the number of times a subject exceeded a PSAV threshold. Cox proportional hazards regression analysis was used to evaluate the associations between the risk count and the probability of high-risk disease. The statistical tests were two-sided. Results: The probability of high-risk disease increased directly with the risk count. After adjusting for age, PSA level, PSAV, and date of diagnosis, the PSAV risk count was significantly associated with the development of high-risk prostate cancer (relative risk 1.41, 95% confidence interval 1.25 to 1.59 for a PSAV cutpoint 0.2 ng/mL/yr; relative risk 1.49, 95% confidence interval 1.29 to 1.71 for a PSAV cutpoint of 0.4 ng/mL/yr; P <0.001). Conclusions: The PSAV risk count could be a useful method of interpreting a PSA history to help identify those men who will benefit from a diagnosis of prostate cancer at PSA levels associated with curable disease.