MP15-15 A RETROSPECTIVE REVIEW OF A LARGE ACTIVE SURVEILLANCE COHORT IN PATIENTS WITH PROSTATE CANCER AT THE CLEVELAND CLINIC

Gleason score undergrading. We compared biochemical recurrence rates (BCR) after radical prostatectomy between patients with active surveillance (AS) suitable prostate cancer versus wider defined low risk prostate cancer and the effect of Gleason score upgrading after surgery. METHODS: Two prostatectomy cohorts were combined. Lowrisk PC was defined as T1-2, Gleason 6 prostate cancer and AS-suitable prostate cancer was defined using the ‘PRIAS-criteria’ as T1-2, PSA 1⁄4<10 ng/ml, PSA density <0.2 ng/ml/ml, 1-2 positive biopsies, Gleason 3+31⁄46. Kaplan-Meier curves of patients with and without Gleason score upgrading were compared using the Log-Rank test. We hypothesized that perfect pre-operative biopsy Gleason grading would lead to 0% upgrading after surgery. RESULTS: We included 755 patients of whom 181 (24%) suitable for AS, 324 (44%) had Gleason upgrading after surgery (to 6.5 in non-AS suitable versus 6.3; p1⁄40.005), and 132 (18%) showed BCR a median of 1.0 year after prostatectomy. For the total group, the 5-year BCR rate was 27%. Regarding the entire low risk group of T1-2 Gleason 6 prostate cancer, Gleason upgrading at surgery was significantly associated with unfavorable BCR rates (Figure 1a; p<0.01). Within the selected group of more favorable risk disease suitable for AS, Gleason upgrading at surgery was not associated with BCR rates (Figure 1b; p1⁄40.936). In patients who did not have Gleason upgrading, patients who were not suitable for AS showed similar BCR rates to patients who did fulfill all AS criteria (Figure 1c; p1⁄40.155). A limitation is the retrospective design; prospective validation is needed. CONCLUSIONS: In the selected group of favorable risk patients considered suitable for AS, no unfavorable effect on BCR rates was found of Gleason undergrading. This may question the additional value of reducing biopsy undergrading with new imaging techniques. In patients not fulfilling the strict AS criteria, exclusion of Gleason upgrading resulted however in BCR rates similarly favorable to patients who were suitable for AS. This may suggest that MRI could be used to expand selection criteria for AS if Gleason upgrading could be excluded.