Impact of tumor size on survival in stage IA non-small cell lung cancer: a case for subdividing stage IA disease

Abstract

Purpose: Stage IA (T1N0M0) non-small cell lung cancer (NSCLC) includes all lesions up to 3 cm in diameter. With the use of advanced imaging techniques, smaller pulmonary lesions can be identified. A greater proportion of patients with NSCLC will likely have smaller tumors at presentation in the future. The purpose of this study was to determine the relationship between tumor size, and survival in patients with pathologic stage IA NSCLC. Methods: We conducted a retrospective review of 246 consecutive, surgically treated patients with pathologic stage IA NSCLC. Eligible patients were identified from the tumor registries and pathology records. Follow-up was obtained from the surgical database and primary physicians’ records. Results: Eighty six patients had tumors ≤1.5 cm while 160 patients had tumors 1.6–3.0 cm. The median follow-up time is 60 months. The patients with the tumors ≤1.5 cm had an improved outcome when compared with patients with tumors 1.6–3.0 cm. The 5-year disease free survival (DFS) was 81.5 and 70.9%, respectively, ( P=0.03) and the 5-year overall survival was 85.5 and 78.6%, respectively ( P=0.05). In the multivariate analysis, tumor size was an independent prognostic factor for survival. Conclusions: Tumor size is a prognostic factor in pathologic stage IA NSCLC treated with adequate surgical resection. Such improvement, not observed in some earlier reports, may represent the effect of improved imaging and pre-operative surgical techniques. This finding requires confirmation in prospective series, but is important since it makes a case for further subdividing T1 lesions in resected NSCLC.