Prognostic significance of subclassification of stage IIB lung cancer: a retrospective study of 226 patients.

We investigated the prognostic significance of subclassification of stage IIB lung cancer according to the eighth tumor-node-metastasis (TNM) classification. To this purpose, the prognostic outcomes of 226 stage IIB lung cancer patients who underwent surgery without adjuvant therapies between 2001 and 2010 were evaluated retrospectively based on the eighth TNM classification. Of the 226 patients, 23, 30, 118 and 55 had pT1b, pT1c, pT2a, and pT2b stage cancers, respectively. Their 5-year survival rates were 67%, 33%, 21%, and 27%, respectively. There was no significant difference in the 5-year survival between T1b and T1c, between T1c and T2a, and between T2a and T2b (p = 0.128, 0.105, and 0.403, respectively). There were significant differences in the 5-year survival between T1b and T2a, between T1b and T2b, and between T1c and T2b (p = 0.005, 0.002, and 0.042, respectively). The 5-year survival of patients with pleural invasion and vessel invasion was significantly worse than that of their counterparts (p = 0.009 and <0.001, respectively). Subclassification of stage IIB lung cancer is of prominent prognostic significance. It is recommended that the current stage be subclassified, in order to more accurately predict the prognosis of patients.