Postoperative radiotherapy is effective in improving survival of patients with stage pIII-N2 non-small-cell lung Cancer after pneumonectomy

BACKGROUND: There were few reports of postoperative radiotherapy (PORT) in stage pIII-N2 Non-small-cell Lung Cancer (NSCLC) patients receiving pneumonectomy followed by adjuvant chemotherapy. This study aims to evaluate safety and efficacy of PORT among these patients. METHODS: Between Jan. 2004 and Dec. 2015, stage pIII-N2 NSCLC patients receiving pneumonectomy and adjuvant chemotherapy with or without PORT in our institution were retrospectively reviewed. RESULTS: Totally 119 patients were included, 32 patients receiving adjuvant chemotherapy and PORT (PORT group) and 87 receiving adjuvant chemotherapy alone (Control group). There were more patients with non-R0 resection in PORT group than Control group (25% vs. 8%, p = 0.031). In PORT group, ≥Grade 2 radiation-induced pneumonitis was 2/32. No severe radiation-related heart injury was observed. There was no PORT-related death. Of all patients, median follow-up time was 25 months. Median overall survival time (mOS) and median disease-free survival time (mDFS) were 46 months and 15 months, respectively. The PORT group had significantly better OS (not reached vs. 34 months, p = 0.003), DFS (19 months vs. 13 months, p = 0.024), local recurrence free survival (LRFS, p = 0.012), and distant metastasis free survival (DMFS, p = 0.047) than the Control group. As for failure pattern, PORT significantly reduced local regional failure rate (39.1% vs. 15.6%, p = 0.016). In subgroup analysis, patients with R0 resection (n = 104), OS and LRFS in PORT group were significantly longer, and PORT tended to increase DFS and DMFS. CONCLUSION: For patients with stage pIII-N2 NSCLC after pneumonectomy and adjuvant chemotherapy, PORT can improve OS, DFS, LRFS and DMFS with tolerable toxicity.