Size of Stage IIIA Primary Lung Cancers and Survival: A Surveillance, Epidemiology and End Results Database Analysis

Abstract

Size of early-stage lung cancer is important in the prognosis of patients. We examined the large population-based Surveillance, Epidemiology and End Results database to determine if tumor size was an independent risk factor of survival in patients undergoing lobectomy for N2 positive Stage IIIA nonsmall cell lung cancer (NSCLC). This study identified 1971 patients diagnosed with N2 positive Stage IIIA NSCLC, from 1998 to 2007, and who underwent lobectomy. Five tumor groups based on the seventh edition TNM lung cancer staging system (pathologic T1a 2 cm or less; T1b greater than 2 cm and 3 cm or less; T2a greater than 3 cm and 5 cm or less; T2b greater than 5 cm and 7 cm or less; T3 greater than 7 cm) were analyzed. Survival was reduced in patients with T3, T2a, and T2b tumors compared with patients with T1a and T1b ( P < 0.001). Survival estimates correlated with tumor size with poorer survival in T3 followed by T2b, T2a, and then T1b and T1a. Cohorts with T1a (hazard ratio [HR], 0.53; P = 0.01) and T1b (HR, 0.54; P = 0.01) were both found to have decreased hazard of death. Negative predictors of survival, in addition to increasing tumor size, included age and male gender, whereas positive predictors included tumor Grade I and upper lobe location. Increasing size of tumor is an independent negative risk factor for survival in patients undergoing lobectomy for N2 positive Stage IIIA NSCLC.

Relationship between tumor size and survival in non-small cell lung cancer (NSCLC): An analysis of the Surveillance, Epidemiology, and End Results (SEER) registry.

“…Two recent SEER database-based studies with a larger number of patients have attempted to investigate the prognostic significance of tumor size in patients with locally advanced NSCLC and both showed tumor size to be an independent prognostic factor. 34,35 However, both studies were focused on stage III disease, while node-positive stage IIA and IIB disease were not included. To the best of our knowledge, our study is the first comprehensive populationbased study with the largest sample size including node-negative and node-positive NSCLC, evaluating the impact of primary tumor size on survival according to both nodal involvement and extent / invasiveness of primary tumor.…”

“…In previous studies, including the two SEER-based studies on stage III NSCLCs, 34,35 tumor size was subclassified into categorical variables, thus potentially resulting in underestimation of the extent of variation in survival among groups and concealing nonlinearity in the relation between tumor size and survival. In contrast, to best utilize the information on tumor size, we looked at tumor size as a continuous variable in the multivariate models, potentially improving prediction accuracy.…”