Is It Time to Revisit the Role of Prostate-specific Antigen Kinetics in Active Surveillance for Prostate Cancer?

Objective: To identify factors that are not available at the time of prostate cancer diagnosis and are associated with the risk of biopsy progression in active surveillance (AS) patients. Materials and Methods: The study included 314 AS patients who had at least 1 repeat biopsy. We used logistic regression to analyze the association between prostate-specific antigen (PSA) and its derivatives, including PSA density, PSA velocity (PSAV) and doubling time (PSADT); presence of bilateral disease and number of previous successive negative surveillance biopsies; and the risk of progression on the surveillance biopsies first through fourth. Results: Over a median follow-up of 3.1 years, patients had a mean of 2.4 biopsies. The median time from diagnosis to the last biopsy was 2.3 years. The biopsies were performed at fairly equal intervals. For surveillance biopsies 1 through 3, none of the studied factors was adding significant prognostic information to the baseline characteristics. PSAV and PSADT were associated with the risk of progression on the fourth biopsy; this association was independent of baseline characteristics. No progression on the fourth biopsy was noted in 23 patients with negative PSAV. Among 54 patients with PSADT of more than 3 years only, 2 progressed whereas 6 out of 9 patients with a PSADT less than 3 years had biopsy progression on the fourth surveillance biopsy. Conclusion: PSA kinetics may be helpful in defining the indications for prostate biopsy in AS patients who are followed with regular biopsies for more than 3-4 years.