Adjuvant chemotherapy improves survival outcomes after complete resection of thymic squamous cell carcinoma: a retrospective study of 116 patients.

Abstract

The aim of this study was to evaluate the efficacy of adjuvant chemotherapy (ACT) for thymic squamous cell carcinoma after completely resection. Patients with thymic squamous cell carcinoma treated with complete resection between January 2009 and December 2016 were retrospectively identified. Kaplan-Meier analysis was used to summarize the time-to-event variables. Univariable and multivariable Cox proportional hazards regression analyses were performed. A total of 116 patients were analysed with 44 patients in the non-ACT group and 72 patients in the ACT group. No significant difference was found in the 5-year recurrence-free survival (RFS) rate (58.1% vs 51%, P = 0.33) or the 5-year overall survival (OS) rate (77.7% vs 67.1%, P = 0.26) between the ACT group and the non-ACT group. Masaoka stage was the only independent prognostic factor for both RFS and OS. Subgroup analysis showed significant improvement in 5-year RFS for Masaoka stage II patients (P = 0.035) and 5-year OS (P = 0.036) for Masaoka stage III patients when comparing ACT with non-ACT. No chemotherapy-related death occurred. The most frequent adverse effect higher than grade 3 was neutropenia. For completely resected thymic squamous cell carcinoma, ACT significantly improved the 5-year RFS in Masaoka stage II patients and the 5-year OS in Masaoka stage III patients.