Radical prostatectomy for low-risk prostate cancer following initial active surveillance : results from a prospective observational study

BACKGROUND: Little is known about the outcome of radical prostatectomy (RP) in men initially followed on active surveillance (AS) for low-risk prostate cancer (PCa). OBJECTIVE: Evaluate pathology findings after RP in our prospective AS cohort. DESIGN, SETTING, AND PARTICIPANTS: All men participated in the Prostate Cancer Research International: Active Surveillance (PRIAS) study. Eligible men were initially diagnosed with low-risk PCa (clinical stage ≤ T2, prostate-specific antigen [PSA] ≤ 10 ng/ml, PSA density <0.2 ng/ml per ml, one or two positive biopsy cores, and Gleason score ≤ 6) and underwent RP between December 2006 and July 2011. The study protocol recommends RP in case of risk reclassification on repeat biopsy (Gleason score >6 and/or more than two positive cores) or a PSA doubling time ≤ 3 yr. MEASUREMENTS: Descriptive statistics were used to report on pathology findings for staging and grading. RESULTS AND LIMITATIONS: Pathology results were available in 167 out of 189 RP cases (88.4%). Median time to RP was 1.3 yr (range: 1.1-1.9). Protocol-based recommendations led to deferred RP in 143 men (75.7%); 24 men (12.7%) switched because of anxiety, and 22 (11.6%) had other reasons. Pathology results showed 134 (80.8%) organ-confined cases and 32 (19.2%) cases with extracapsular extension. Gleason scores ≤ 6, 3+4, 4+3, and 8 were found in 79 (47.3%), 64 (38.3%), 21 (12.6%), and 3 (1.8%) cases, respectively. Unfavourable RP results (pT3-4 and/or Gleason score ≥ 4+3) were found in 49 patients (29%), of whom 33 (67%) had a biopsy-related reason for deferred RP. CONCLUSIONS: RP results in men initially followed on AS show organ-confined disease and favourable Gleason grading in a majority of cases. Most men in our cohort had a protocol-based reason to switch to deferred RP. A main focus for AS protocols should be to improve the selection of patients at the time of inclusion to minimise reclassification of risk and preserve the chance for curative treatment, if indicated.