Etoposide and Cisplatin (EP) for Metastatic Good-Risk Germ Cell Tumors (gcts): the Memorial Sloan-Kettering Cancer Center (MSKCC) Experience in 944 Patients (Pts).

4550 Background: Standard of care for pts with metastatic, good-risk GCTs consists of either 3 cycles of bleomycin, etoposide, and cisplatin (BEPx3) or 4 cycles of EP (EPx4). EPx4 avoids both pulmonary and vascular bleomycin toxicity. Methods: 944 pts with good-risk GCTs (LDH modified to < 3 x upper limit of normal) were treated with EPx4 at MSKCC from1982 to 2015. EP consisted of cisplatin 20mg/m2 and etoposide 100mg/m2 on days 1 to 5 at 21-day intervals. Response, post-EP surgical findings, and survival were obtained for 655 pts treated from 2000 to 2015 and compared with the same outcomes plus updated follow-up for 289 pts treated from 1982 to 2002 previously reported by Kondagunta et al. (JCO, 2005). Results: Of the recent 655 pts, median age was 33 (range, 15-77), nonseminoma comprised 65%, seminomas 35%, AFP elevated in 27%, HCG 53%, and LDH 31% with 7.6% of nonseminoma with LDH 1.5 - 3 times upper limit of normal. 97% pts completed 4 cycles of EP. Of 655 pts, 313 underwent post-EP retroperitoneal lymph node dissection (RPLND): 59.1% necrosis or fibrotic debris, 38.0% pure teratoma, 2.6% viable, non-teratomatous GCT, 1 patient unclassified. Febrile neutropenia and thromboembolic events occurred in 15.9% and 8.9%, respectively. In the combined group of 944 pts, 927 (98.2%) achieved a favorable response (CR or PR-negative markers); there was 1 treatment-related death. With median follow up for the combined 944 pt group of 6.8 years, five-year PFS and OS rates were 93.4% and 97.9%, respectively. Outcomes summarized in the table. Conclusions: In the largest series of good-risk pts treated with EPx4 ever reported, our results confirm that this regimen is highly effective and well-tolerated. EPx4 remains a standard treatment option for good-risk GCT and remains the preferred regimen at MSKCC. JCO 2005 Current Updated Total (%) Number of Pts 289 655 944 Favorable Response (%) 282 (98) 645 (98) 927 (98) Viable, non-teratomatous GCT at Post-EP Surgery (%)* 11/134 (8) 8/313 (3) 19/447 (4) Relapse (%) 18 (6)^ 26 (4) 44 (5) Died of Disease (%) 10 (3)^ 4 (1) 14 (2) *JCO 2005 includes any post-EP surgery. Current limited to RPLND.^1 pt relapsed and died of disease post-publication