Ultra-early versus early salvage androgen deprivation therapy for post-prostatectomy biochemical recurrence in pT2-4N0M0 prostate cancer

BACKGROUND The optimal timing of salvage androgen deprivation therapy (ADT) for biochemical recurrence after radical prostatectomy is controversial. We compared the outcomes of ultra-early versus early salvage ADT. METHODS Among 855 patients undergoing radical prostatectomy at our institution between 2000 and 2012, we identified 121 with adjuvant-treatment-naïve pT2-4N0M0 prostate cancer who received salvage ADT for biochemical recurrence. These patients were divided into an ultra-early salvage ADT group (n = 51), who started salvage ADT before meeting the standardized definition of biochemical recurrence in Japan (two consecutive prostate-specific antigen [PSA] values ≥0.2 ng/ml), and an early salvage ADT group (n = 70) who started salvage ADT when they met the definition. The ultra-early ADT group consisted of those who started salvage ADT with a single PSA value ≥0.2 ng/ml (n = 30) or with two consecutive PSA values >0.1 ng/ml and rising (n = 21). The primary endpoint was biochemical recurrence after salvage ADT, defined as a single PSA value ≥0.2 ng/ml after PSA nadir following salvage ADT. Secondary endpoints were clinical metastasis and cancer-specific survival. A Cox proportional hazards model was used for multivariate analysis. The median follow-up was 65.5 months. RESULTS Biochemical recurrence occurred in one patient (2.0%) in the ultra-early group and in 12 (17.1%) in the early salvage ADT group. Multivariate analysis identified ultra-early salvage ADT and preoperative Gleason score ≤7 as independent negative predictors of biochemical recurrence after salvage ADT. Only one patient in the early salvage ADT group developed clinical metastasis to a left supraclavicular lymph node, and no patient died from prostate cancer during follow-up. The major limitations of this study were its retrospective design, selection bias, and the possibility that the ultra-early salvage ADT group may have included patients without biochemical recurrence. CONCLUSIONS Ultra-early salvage ADT was an independent negative predictor of biochemical recurrence after salvage ADT in post-prostatectomy patients. Further consideration should be given to the use of salvage ADT before meeting the current definition of biochemical recurrence.