MP15-04: Safety and feasibility of salvage radical prostatectomy following primary IRE treatment for recurrent localized prostate cancer: an international and multicenter analysis

Luigi A.M.J.G. van Riel*, Amsterdam, Netherlands, Alexander Blazevski, Darlinghurst, Australia, Ertunc Kabaktepe, Amsterdam, Netherlands, Bart Geboers, Darlinghurst, Australia, Daan Reesink, Pascal Stijns, Nieuwegein, Netherlands, Philip D. Stricker, Darlinghurst, Australia, Juan Casanova, Jose Luis Dominguez-Escrig, Valencia, Spain, Theo M. de Reijke, Matthijs J. Scheltema, Jorg R. Oddens, Amsterdam, Netherlands

Introduction: Irreversible electroporation (IRE) is among the available ablative techniques in carefully selected prostate cancer (PCa) patients. Yet, there is a risk of recurrence leading to the need for salvage therapy. It is unknown whether initial IRE treatment jeopardizes functional and oncological outcomes following salvage radical prostatectomy (sRP) for recurrent localized PCa. The aim of this study is to evaluate safety, feasibility, functional and short-term oncological outcomes of sRP for recurrent localized PCa after initial primary IRE treatment.

Methods: An international, multicenter and retrospective analysis of prospectively collected data of patients that underwent sRP for recurrent localized PCa after initial primary IRE treatment. Data were reported on functional outcomes (urinary continence and erectile function), quality of life and oncological outcomes (time interval between IRE and sRP, pathology, overall survival) and safety (surgical complications) and feasibility of sRP (as reported by surgeons).

Results: : In four participating centers a total of 39 patients with a median (IQR) age of 64 (7.0) years were identified that underwent sRP following initial IRE treatment. Median (IQR) time to recurrence after IRE was 14.3 (29.8) months. sRP was feasible without dissection difficulties and serious adverse events. Location of recurrence was observed in-field the initial IRE ablation zone in 23 patients (59%), see Figure 1. Significant positive surgical margin (PSM) rate was 15.4%. A persistent detectable PSA was found in one case post-sRP (2.6%), caused by metastatic disease. One patient (2.6%) had a biochemical recurrence 6 months following sRP. These two cases, together with a PSM case, required additional therapy following sRP. Overall survival was 100% with a median (IQR) follow-up duration of 6.9 (12.2) months. At last follow-up urinary continence and erectile function were preserved in 26 patients (76.5%) and 14 patients (41.2%), respectively, while quality of life remained stable.

Conclusions: sRP is safe and feasible for PCa patients with recurrent localized disease following initial IRE treatment. Functional outcomes following sRP seem comparable to primary RP.

Source of Funding: Cure for Cancer foundation.