Potential consequences of low biopsy core number in selection of patients with prostate cancer for current active surveillance protocols

Abstract

Objective: To compare the performance of the Epstein criteria and the Prostate Cancer Research International: Active Surveillance (PRIAS) criteria in the identification of patients eligible for active surveillance (AS) but treated with radical prostatectomy.

Materials and methods: We evaluated the baseline characteristics, final pathologic examination, and prostate-specific antigen follow-up (median 43 months, range 1-118) in a series of 492 consecutive patients with prostate cancer managed by radical prostatectomy without AS from 2001 to 2011 at a single institution. Using the postoperative histologic findings, multivariate analysis was used to identify the preoperative predictors of unfavorable AS selection (Gleason score >6 and/or greater than stage pT2c on the final pathologic examination). Biochemical recurrence-free survival was compared between favorably and unfavorably selected patients.

Results: Applying the Epstein and PRIAS criteria, 29.2% and 32.2% of the patients had Gleason score >6 or stage pT3 on final pathologic examination, respectively. After a median follow-up of 35.5 and 38 months, 4.2% and 4.3% of patients developed biochemical recurrence in the Epstein and PRIAS criteria groups, respectively. Patients with unfavorable selection had significantly worse biochemical recurrence-free survival than patients with favorable selection (P <.05). Although the median biopsy core number was 8, a biopsy core number <9 was a significant and independent predictor for unfavorable preoperative AS selection in the PRIAS group.

Conclusion: We found a non-negligible risk of underestimating unfavorable cancer in patients theoretically qualifying for AS in our cohort. The current use of a sufficient number of biopsy cores might improve the selection process for AS.