Optimal timing of salvage radiotherapy for biochemical recurrence after radical prostatectomy: is ultra-early salvage radiotherapy beneficial?

Satoru Taguchi,Tetsuya Fujimura,Teppei Morikawa,Keiichi Nakagawa,Yuta Takeshima,Yukio Homma,Haruki Kume,Shigenori Kakutani,Tohru Nakagawa,Hiroshi Fukuhara,Akihiro Naito,Kenshiro Shiraishi,Hideyo Miyazaki

doi:10.1186/s13014-016-0671-1

Abstract

BackgroundThe optimal timing of salvage radiotherapy for biochemical recurrence after radical prostatectomy is controversial. In particular, the prognostic significance of salvage radiotherapy delivered before a current definition of biochemical recurrence, i.e. ultra-early salvage radiotherapy, is unclear.MethodsWe reviewed 76 patients with pT2-3N0M0 prostate cancer who underwent salvage radiotherapy for post-prostatectomy biochemical recurrence at the following three timings: ultra-early salvage radiotherapy (n = 20) delivered before meeting a current definition of biochemical recurrence (two consecutive prostate-specific antigen [PSA] values ≥0.2 ng/mL); early salvage radiotherapy (n = 40) delivered after meeting the definition but before PSA reached 0.5 ng/mL; and delayed salvage radiotherapy (n = 16) delivered after PSA reached 0.5 ng/mL. The primary endpoint was failure of salvage radiotherapy, defined as a PSA value ≥0.2 ng/mL. The log-rank test and Cox proportional hazards model were used for univariate and multivariate analyses, respectively.ResultsDuring the follow-up period (median: 70 months), four of 20 (20 %), nine of 40 (23 %) and seven of 16 (44 %) patients failed biochemically in the ultra-early, early and delayed salvage radiotherapy groups, respectively. On univariate analyses, the outcome of delayed salvage radiotherapy was worse than the others, while there was no significant difference between ultra-early and early groups. Multivariate analysis demonstrated the presence of Gleason pattern 5, perineural invasion and delayed salvage radiotherapy as independent predictors of poorer survival.ConclusionsNo survival benefit of ultra-early salvage radiotherapy was demonstrated, whereas delayed salvage radiotherapy was associated with worse outcome as reported in previous studies. Our results may support the current recommendations that salvage radiotherapy should be undertaken after two consecutive PSA values ≥0.2 ng/mL and before reaching 0.5 ng/mL.

Highlights

The optimal timing of salvage radiotherapy for biochemical recurrence after radical prostatectomy is controversial
We previously reported that salvage androgen deprivation therapy (ADT) administered before meeting the Japanese definition, referred to as “ultra-early salvage ADT”, achieved a better oncological outcome than ADT administered after patients met the definition in pT2-4 N0 prostate cancer (PC) [8]
The outcome of delayed salvage radiotherapy (SRT) (dSRT) was significantly worse than the others, while there was no significant difference between ultra-early salvage radiotherapy (ueSRT) and early SRT (eSRT) (P = 0.6171, Fig. 1)

Summary

Introduction

The optimal timing of salvage radiotherapy for biochemical recurrence after radical prostatectomy is controversial. The prognostic significance of salvage radiotherapy delivered before a current definition of biochemical recurrence, i.e. ultra-early salvage radiotherapy, is unclear. 25–35 % of patients develop biochemical recurrence (BCR) after radical prostatectomy (RP) for clinically localized prostate cancer (PC) [1, 2]. We previously reported that salvage androgen deprivation therapy (ADT) administered before meeting the Japanese definition, referred to as “ultra-early salvage ADT”, achieved a better oncological outcome than ADT administered after patients met the definition in pT2-4 N0 PC [8]. Briganti et al demonstrated that early SRT (eSRT; given at pre-radiation PSA ≤0.5 ng/mL) achieved an oncological outcome equivalent to adjuvant radiotherapy in patients with pT3N0 PC [10]

Methods

Results

Discussion

Conclusion