Validation of 7th TNM staging system for lung cancer, based on surgical outcomes

Background: Validation of the clinical classification for lung cancer of the 7th edition of the TNM staging system among surgical cases has not been reported previously. Methods: Data of 489 males and 246 females, with a mean age of 67.6 years, who underwent surgical resection for nonsmall- cell lung cancer were analyzed retrospectively. Results: The 5-year survival rate of these patients was 72.2% for clinical stage IA (n=365), 58.4% for IB (n=158), 51.2% for IIA (n=77), 49.1% for IIB (n=42), 36.8% for IIIA (n=86), 80% for IIIB (n=5) and 50% for IV (n=2). The 5-year survival rate of patients was 100% for pathological stage 0 (n=2), 86.1% for IA (n=216), 73.8% for IB (n=173), 46.1% for IIA (n=97), 47.2% for IIB (n=69), 33.3% for IIIA (n=155), 33.3% for IIIB (n=3) and 30.9% for IV (n=20). Prognostic factors included female sex and 70 years of age or younger, as well as adenocarcinoma histology. Conclusions: Deterioration in patient survival was indicated with the exception of stages IIIB and IV, each of which included only a small number of patients. Our study validated the current TNM staging system in surgical cases with regard to both clinical and pathological classifications.