Evaluation of the 7th edition of the TNM classification for lung cancer at a single institution

To assess the utilities and drawbacks of the 7th edition of the TNM classification for lung cancer. Subjects included 1,469 patients who underwent pulmonary resection for primary non-small cell lung cancer. Survival characteristics were compared using the 6th and 7th editions of the staging system. According to the 6th and 7th editions, respectively, the 5-year survival rates based on stages were as follows: pStage IA (81.0, 81.0 %), pStage IB (70.6, 72.0 %), pStage IIA (61.3, 59.7 %), pStage IIB (56.6, 47.2 %), pStage IIIA (43.4, 37.6 %), pStage IIIB (8.9, 14.9 %), and pStage IV (14.0, 8.0 %). According to the 6th edition, there was no significant difference between pStages IB and IIA (P = 0.268), or between pStages IIA and IIB (P = 0.622), or between pStages IIIB and IV (P = 0.737). According to the 7th edition, there were significant differences between each adjacent stage group, except between pStages IIIB and IV (P = 0.424). According to the 7th edition staging system, 5-year survival rates by T classification were as follows: pT1a, 81.6 %; pT1b, 75.9 %; pT2a, 60.1 %; pT2b, 44.7 %; pT3, 24.4 %; and pT4, 13.2 %; with significant differences between each adjacent pT classification. The 5-year survival rates by M classification were as follows: M0, 57.2 %, M1a, 9.1 %, M1b, 0 %, with a significant difference between M0 and M1a, but there was no significant difference between M1a and M1b. The UICC 7th edition staging system is considered valid for non-small cell lung cancer patients and appears to be superior in defining different prognostic groups than the 6th edition.