Surgical outcomes of patients with stage III thymoma in the Japanese nationwide database

Background To investigate the clinical characteristics and therapeutic outcomes of patients who underwent surgery for stage III thymoma in Japan. Methods Using the Japanese nationwide database, which contains the records of 2,835 patients with thymic epithelial tumors who underwent treatment between 1991 and 2010, we extracted and analyzed the records of those who underwent surgery for stage III thymoma. Results A total of 310 patients (170 males, 140 females; median age, 58 years) were analyzed. Involved sites were the lung in 194 (62.6%), the pericardium in 151 (48.7%), the great vessels in 126 (40.6%), the phrenic nerve in 84 (27.1%), and the chest wall in 7 (2.3%). Complete resection (R0) was achieved in 247 (79.7%) cases. Induction therapies were administered to 42 (13.5%) patients, and postoperative therapies were administered to 147 (47.4%). In R0 cases, 68 (27.5%) experienced recurrence. The pleural space was the most frequent site of recurrence (46; 18.6%). The 10-year overall and disease-free (in R0) survival rates were 80.2% and 51.6%, respectively. Multivariate analyses revealed that age (p = 0.002), male sex (p = 0.017), induction therapy (p < 0.001), and type B histology (p = 0.037) were independent adverse predictors for overall survival. Chest wall invasion was the only independent adverse predictor for disease-free survival, although the factor analysis was marginal for overall survival. Conclusions The outcomes of surgery for patients with stage III thymoma were favorable unless chest wall invasion was present; however, the role of complete resection and appropriate multimodal treatment plan require further investigation.