Impact of Gleason pattern 5 including tertiary pattern 5 on outcomes of salvage treatment for biochemical recurrence in pT2-3N0M0 prostate cancer.

Background: Gleason pattern 5 (GP5), including tertiary GP5, at radical prostatectomy has reportedly been associated with poorer clinical outcome. However, it is undetermined how tertiary GP5 is handled in the new Gleason grade grouping starting in 2016, and its prognostic value in patients undergoing salvage treatment for postoperative biochemical recurrence (BCR) remains unclear.

Methods: We retrospectively reviewed 116 patients with pT2-3N0M0 prostate cancer (PC) who received salvage treatment for BCR after radical prostatectomy between 2003 and 2014. The primary endpoint was failure of salvage treatment, defined as a single prostate-specific antigen (PSA) value ≥0.2 ng/ml after PSA nadir following salvage treatment. Associations of various clinicopathological factors, including GP5, with failure-free survival were assessed. Cox proportional hazards model was used for multivariate analysis.

Results: Patients received salvage treatment with either radiotherapy (n = 48), androgen-deprivation therapy (n = 61), or both (n = 7) for BCR. Twenty-three patients (19.8 %) experienced failure of salvage treatment, with a median follow-up period of 79 months. Univariate analysis associated GP5, Gleason score-based parameters, lymphovascular invasion, and PSA doubling time <6 months with poorer failure-free survival. Receiver operating characteristic curve analyses identified the area under the curve for GP5 (0.654) as the largest among those parameters (P = 0.0060). Multivariate analysis demonstrated that GP5 was the only independent predictor of poor outcome.

Conclusions: The presence of GP5 is an independent predictor of poor prognosis in patients with pT2-3N0M0 PC undergoing salvage treatment for BCR after radical prostatectomy. GP5 may thus be a more useful marker than conventional Gleason score in this setting.