Clinical outcomes of minimally invasive retroperitoneal lymph node dissection and single dose carboplatin for clinical stage IIa seminoma.

Abstract

530 Background: Standard management of Stage 2 seminoma (SEM) is 3 cycles of cisplatin based multi-agent chemotherapy or paraaortic/pelvic radiotherapy. Both treatments have potential short and long term toxicity. We report the use of minimally invasive (robotic or laparoscopic) retroperitoneal lymph node dissection (MI-RPLND) and adjuvant carboplatin. Methods: From 01/2013-04/2017, patients (pt) with SEM and Stage 2a disease on computed tomography (CT) staging scan were considered for MI-RPLND included the radiologically enlarged lymph nodes for Stage 2a SEM. Adjuvant carboplatin (AUC 7) x 1 cycle was administered after confirmation of nodal involvement. Post-operative outcomes including length of stay, Clavien-Dindo 1 complications and pathological staging were recorded. CT was performed at 3 months to verify nodal clearance and then pts monitored with a standard surveillance protocol. Results: Twenty modified unilateral templates were performed. Median and mean post-operative stay was 1 and 1.5 days. One pt required conversion to open surgery and two experienced Clavien-Dindo 1 complications. All pts had preserved ejaculation. Mean number of nodes removed per pt 14.3 (range 5-31) with average 1.75 nodes involved (range 0-5). In 2 pts the enlarged nodes were pN0; they were surveyed and are relapse free at 44+ months. In one case the enlarged lymph node contained embryonal carcinoma (EC) despite primary histology of pure SEM. The remaining 17 pts had confirmed pathological stage 2 SEM. The pt with EC and one pt who had adjuvant carboplatin for stage 1 disease received (B) EP x 2 cycles. 16 patients received a single cycle of adjuvant carboplatin (AUC 7). After median follow-up of 41 months (range 22-70), one patient has relapsed. This occurred at 18 months outside the template of dissection. This patient initially had multifocal disease with 3 pathologically involved nodes. He received BEP X 3 with complete radiological resolution of disease and remains disease free. Conclusions: MI-RPLND in conjunction with a single dose of carboplatin may potentially be an option for the management of Stage 2a SEM. In this series, a subset of pts were overstaged using standard CT imaging.