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.