Reducing the rate of biopsy Gleason undergrading may not improve biochemical recurrence rates in active surveillance candidates.

Abstract

BACKGROUND: To explore the impact of improved risk stratification on biochemical recurrence (BCR) rates after surgery in prostate cancer (PC) patients also suitable for active surveillance (AS). Patients with Gleason upgrading were compared to those who were correctly graded with biopsy. Also, to analyze whether AS criteria may be expanded, by comparing patients outside the AS criteria without Gleason upgrading, to men eligible for AS. METHODS: Low-risk PC was widely defined as clinically organ-confined and biopsy Gleason score =<3+3=6. Within this group, additional AS eligibility criteria were PSA =<10 ng/ml, PSA density <0.2 ng/ml/cc, and 1-2 positive biopsies. RESULTS: Of 755 clinically organ-confined low-grade patients, 181 (24%) were suitable for AS, 324 (44%) had Gleason upgrading after surgery, and 132 (18%) showed BCR after a median follow-up of 1.8 years (25-75p 0.7-3.4). Gleason upgrading between biopsy and surgery score was significantly associated with unfavorable BCR rates (p<0.01) in clinically organ-confined low-grade patients, but it did not impact BCR in AS-suitable patients (p=0.936). Clinically organ-confined low-grade patients without Gleason score upgrading showed BCR rates similar to patients who did fulfill all AS criteria (p=0.187). CONCLUSIONS: These results may be used to guide application of novel diagnostic (imaging) modalities in selection for AS. The added value of improved Gleason grading may be limited in AS-suitable patients, as Gleason upgrading does not impact BCR. However, in patients outside of the AS criteria in whom Gleason upgrading is excluded, BCR rates are not significantly different from AS- suitable patients, suggesting opportunities to expand AS criteria.