P1.17-001 The Optimal First-Line Treatment for Advanced Thymic Carcinomas

Abstract

Background: Thymic carcinomas (TC) are remarkably rare aggressive tumors. Due to this, the optimal first-line regimen in patients with advanced TC has not been clarified since the previous studies included a relatively small number of TC patients. The purpose of this study was to evaluate the optimal first-line regimen in patients with advanced TC. Method: We conducted a retrospective study in patients with advanced TC from 2006 to 2015. The primary end point of this study was to evaluate the objective response rate (ORR) and progression free survival (PFS) of different chemotherapy regimens. Age, gender, stage (IVa or IVb), radiation therapy after chemotherapy, resection of primary lesion, different chemotherapy regimens and cycles of chemotherapy were analyzed for significance on PFS. Multivariate Cox model was used to identify significant factors. Result: Sixty-seven patients with stage IV (Masaoka stage) TC were enrolled. Thirty-six patients were treated with paclitaxel-platinum regimen every 3 weeks for a maximum of six cycles. Thirty-one patients were treated with gemcitabine-platinum regimen every 3 weeks for a maximum of six cycles. Resections of primary lesion were performed in fourteen patients before chemotherapy. Thirtythree out of 67 patients were given radiation therapy after chemotherapy. Multivariate analysis demonstrated that different stages (HR ¼ 2.47, P ¼ 0.003), surgical resection (HR ¼ 0.32, P¼ 0.0049) and radiation therapy after chemotherapy (HR ¼ 0.32, P¼ 0.0001) were significantly associated with PFS. The ORR were 31% (11/36) and 29% (9/31) in paclitaxel-platinum regimen group and gemcitabine-platinum regimen group (P¼0.89), respectively. The median PFS, 1-/2-year PFS rates in paclitaxel-platinum regimen group were 7.0 (95% CI 4.0e8.0) months, 26%/6% respectively compared to 12 months (95% CI 11.2e24.0), 48%/24% in gemcitabine-platinum regimen group (P¼0.03). The median PFS, 1-/2year PFS rates were 18.0 (95% CI 12.0e36.0) months/7.3(95% CI