Node-Negative Non-small Cell Lung Cancer: Pathological Staging and Survival in 1765 Consecutive Cases

IntroductionThis study aimed to evaluate prognostic factors in patients with node-negative non-small cell lung cancer and to assess revised International Association for the Study of Lung Cancer staging recommendations for this group.MethodsA retrospective analysis of 1765 consecutive pathologically node-negative patients treated by surgical resection between 1984 and 2007 was performed. Survival analysis was conducted using the Kaplan-Meier method. The independence of prognostic factors was analyzed using multivariate Cox proportional hazards modeling.ResultsThe median age of patients was 68 years, and the average length of follow-up was 6.3 years. Perioperative mortality was 1.7%. The median survival was 6.5 years, with a 56% of the cohort surviving 5 years. Factors associated with poorer prognosis were male gender (hazard ratio [HR]: 1.30, p = <0.001), age (HR: 1.04 per year of increase, p < 0.001), limited resection (HR: 1.30, p = 0.002) tumor size (HR: 1.10 per 10 mm increase, p < 0.001), large cell histopathological cell type (HR: 1.35, p < 0.001), and positive resection margins (HR: 1.58, p = 0.002). T stage was a superior predictor of survival than tumor size (p < 0.001). There was no difference in survival by T-stage descriptor within stage T2 or T3.ConclusionsIn surgically treated, node-negative non-small cell lung cancer, revised International Association for the Study of Lung Cancer staging criteria stratify survival well. Age, gender, and extent of resection are also important predictors of survival. Current T-stage descriptor groupings are appropriate.