Adjuvant etoposide plus cisplatin (EP) for pathologic stage (PS) II nonseminomatous germ cell tumor (NSGCT).

Abstract

567 Background: The risk of relapse after primary retroperitoneal lymph node dissection (RPLND) for patients (pts) with PS IIA NSGCT is 10-20% and increases to over 50% for pts with PS IIB NSGCT. Cisplatin-based chemotherapy reduces the relapse risk to approximately 1%. Standard adjuvant chemotherapy regimens consist of 2 cycles of EP or 2 cycles of bleomycin plus EP (BEP). Methods: From March 1989 to April 2016, 156 pts with PS II NSGCT seen at Memorial Sloan Kettering Cancer Center and assigned to two cycles of EP chemotherapy following RPLND were included. Pts from a prior analysis (Kondagunta, JCO, 2004) were included with updated survival outcomes and expanded histopathologic parameters. Each cycle consisted of cisplatin 20mg/m2 and etoposide 100mg/m2 administered on days 1 to 5 at 21-day intervals. Demographics, histopathologic features, therapeutic and survival outcomes were recorded. Results: Median age was 28 years (range 15-52). 30 pts (19%) had pN1 disease, 122 (78%) pN2 disease and 4 (3%) pN3 disease. Median number of positive lymph nodes was 3 (range 1-37) and median size of the largest positive node was 2.0cm (range 0.4-7.0cm). 69 pts (45%) had extranodal tumor extension. Embryonal carcinoma, seminoma, mature teratoma and yolk sac were the predominant histological subtypes in the RPLND pathology in 115 (90%), 8 (6%), 4 (3%) and 1 (1%) pts respectively. 150 pts (96%) received 2 cycles of EP, 5 (3%) received 1 cycle of EP and one received 4 cycles of EP due to a transient marker increase following his first cycle. Dose delays occurred in 54 (38%) pts, mostly due to neutropenia (44/54 delays). With a median follow-up of 9 years, 2 pts (1 pN2 and 1 pN3) relapsed; both achieved a complete response to paclitaxel, ifosfamide and cisplatin (TIP), remaining disease-free at 65 and 143 months respectively. 3 pts died, all unrelated to GCT or treatment, for 10-year relapse-free and overall survival rates of 98% and 99%, respectively. Conclusions: This is the largest series reported to date on adjuvant chemotherapy with EP for PS II NSGCT. With 100% disease-specific survival and acceptable toxicity, these data confirm the efficacy of 2 cycles of EP and suggest that inclusion of bleomycin (e.g. BEP) in this setting is not necessary.