The long-term outcome of postoperative radiotherapy and prognostic factors in 259 thymoma patients

Objective: To analyze the prognostic factor's of 259 patients with pathologically confirmed thymorea treated by postoperative radiotherapy in Cancer Hospital, Fudan University. Methods: According to Masaoka staging criteria, there were 55 stage I, 56 stage II , 131 stage III and 17 stage IV lesions. Among them, 179 patients underwent gross total resection, 62 subtotal resection, and 18 biopsy alone. Irradiation dose ranged from 2148 cGy to 6691 cGy, with a median of 4939 cGy. Overall survival, disease-free survival, and local control rates were calculated by Kaplan-Meier method and prognostic factors were analyzed by Cox regression model. Results: The overall 5-year survival was 81%, with 94% for stage I, 85% for stage II, 74% for stage III and 36% for stage IV. The overall 10-year survival was 69%, with 85% for stage I, 61% for stage II, 49% for stage III and 24% for stage IV. On multivariate analysis, the Masaoka stage, surgery resection style, capsule invasion, and gender were the independent prognostic factors. Conclusions: The overall 5- and 10-year survival in this group is promising. The Masaoka stage, surgery resection style, and capsule invasion are the independent prognostic factors for thymoma treated by post-operative radiotherapy. (authors)