Prognostic factors in resected pathological N1-stage II nonsmall cell lung cancer

Stage II nonsmall cell lung cancer (NSCLC) has been redefined in the seventh edition of tumour, node, metastasis (TNM) classification for lung cancer. Stages IIa and IIb both contain node-negative (N0) and node-positive (N1) subgroups. The aim of this study was to evaluate the prognostic factors for overall survival in patients with resected N1-stage II NSCLC. Between January 1992 and December 2010, we retrospectively reviewed the clinicopathological characteristics of 163 N1-stage II (T1a-T2bN1M0) NSCLC in patients undergoing curative resection as primary treatment. Median follow-up time was 37.2 months. The 1-, 3- and 5-yr overall survival rates were 85.3%, 62.1% and 43.5%, respectively. Tumour involvement of the hilar/interlobar nodal zone and poorly differentiated histological grade were significant predictors for worse overall survival using multivariate analysis (p=0.001 and p=0.015, respectively). There were trends toward worse overall survival in older patients and those with larger tumour size (p=0.063 and p=0.075, respectively). In resected N1-stage II NSCLC, hilar/interlobar nodal involvement and poorly differentiated histological grade were significant predictors of worse overall survival. The differences in survival between these subgroups of patients may lead to the use of different adjuvant therapies or postsurgical follow-up strategies.