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.