The Role Of Platinum Rechallenge As Second Line Chemotherapy For Metastatic Endometrial Carcinoma.

e17108 Background: Combination chemotherapy with taxane and platinum, with or without anthracycline, has been the standard first-line chemotherapy regime for metastatic endometrial cancer (EC) and there is no standard second-line. The purpose of this study was to evaluate the efficacy of second-line platinum-based chemotherapy in this setting. Methods: We analyzed retrospectively a cohort of patients treated with second line chemotherapy for metastatic EC, from Jan/2005 to Dec/2015, at 2 Brazilian cancer centers. Primary endpoint was the analysis of overall survival between patients treated with platinum rechallenge (PR) compared to other second-line treatments. Overall survival (OS) and progression free survival (PFS) were calculated from the beginning of second line chemotherapy. Platinum free interval (PFI) was defined as the time from last platinum infusion in the first line to the beginning of second line chemotherapy. We used Kaplan-Meier method for survival analysis, log-rank test to compare survival curves, Cox regression to multivariable analysis and Chi-square or Fisher’s exact test were used to compare proportions among groups. Results: A total of 83 patients were evaluated. Median age was 66.2 years, most of them ECOG performance status 1-2 (78%), endometrioid histology (70%) and grade 2 tumors (44%). All patients, but one, received platinum based chemotherapy at first-line. At second-line 44% (36/82) were PR and of them 66.6% had PFI > 6 months. Median follow-up was 27.6m (20.7–34.5m). Re-exposure carboplatin plus paclitaxel achieved higher overall response rate (ORR) compared to other regimens (42.9% vs 13.3%; p = 0.01). Median OS was 9.7 m (7-12.3m) and PFS, 4.1 m (3.4-4.8m). PR was associated with a higher median PFS, 5.2 (2.9-7.5) vs 3.2m (1.7-4.6) for non re-exposed (p = 0.004), and OS, 13.9 (9.48-18.25m) vs 7.9 m (5.32-10.45m) (p = 0.005). PR remain the only factor independently related to OS in multivariate analysis (HR 0.5; 0.25-0.98 CI95%; p = 0.044). Conclusions: Re-exposure to platinum based chemotherapy in second-line for metastatic endometrial cancer is associated with higher response rates, PFS and OS.