Consolidative High-Dose Chemotherapy (Hdct) After Conventional-Dose Chemotherapy (Cdct) As First Salvage Treatment For Male Patients (Pts) With Metastatic Germ Cell Tumors (Mgcts).

336 Background: Some men with mGCTs progressing after response to initial cisplatin-based combination chemotherapy are cured with CDCT as 1st salvage, however, many are not. Prognosis has recently been better defined by the IPFSG prognostic factors. HDCT with autologous stem cell rescue has been routinely offered after CR/PRm- remission with CDCT at our institution over the past two decades. We retrospectively reviewed our data to assess the validity of the IPFSG prognostic factors and evaluate the potential value of this approach.Eligible men with mGCTs progressing after at least 3 cycles of cisplatin-based chemotherapy received after 01 Jan 1990 and treated with cisplatin-based CDCT+/-HDCT (etoposide + carboplatin) were identified and data collected. Pts were classified into risk groups using IPFSG factors, PFS and OS were analyzed and results for CDCT+/-HDCT compared.38 eligible 1st salvage pts had received a median of 4 cycles (range, 1-7) of CDCT. 20 pts received CDCT alone & 18 pts received CDCT+HDCT. Overall median PFS was 24.6 months (95%CI, 7.3-28.7) and overall median OS was 34.6 months (95%CI, 17.2-51.3). Distribution by IPFSG category, 2-year PFS and 3-year OS rates within each risk category were very similar to IPFSG results. Two toxic deaths occurred with CDCT. Pts treated with CDCT+HDCT more often had better responses to 1st-line chemotherapy and pure seminoma histology. Overall pts treated with CDCT+HDCT had improved PFS (HR: 0.18; 95%CI, 0.07-0.51; p=0.001) and OS (HR: 0.25; 95%CI, 0.10-0.65; p=0.004) compared to CDCT alone. Examination by IPFSG risk category showed that the 2-year PFS and 3-year OS rates for CDCT+HDCT was higher in all prognostic groups except for the very high risk which did not have any HDCT pts.The IPFSG prognostic factors were valid in our 1st salvage mGCT pts. The safety of HDCT with etoposide and carboplatin was confirmed. HDCT was associated with improved PFS and OS outcomes, consistent with observations of Lorch et al (JCO 2011). Ideally the value of optimal CDCT+HDCT should be determined in comparison to optimal CDCT as first salvage therapy in men with metastatic GCT in a randomized trial.