Difference in Postsurgical Prognostic Factors between Lung Adenocarcinoma and Squamous Cell Carcinoma

Purpose: The aim of this study was to compare the clinicopathologic prognostic factors between patients who underwent lung resection for adenocarcinoma (AD) and those with squamous cell carcinoma (SQ). Methods: A database of patients with lung AD or SQ who underwent surgery with curative intent in our department from January 2008 to December 2014 was reviewed. Associations between various clinicopathologic factors, postsurgical recurrence-free survival (RFS), and overall survival (OS) were analyzed to find significant prognostic factors. Results: A total of 537 lung cancer patients (AD, 434; SQ, 103) were included in this study. Although RFS was similar in patients with AD and SQ, OS was significantly poorer in those with SQ. Multivariate analysis in patients with AD revealed that age (>= 69 vs. <69), lymphatic invasion, and histologic pleural invasion (p0 vs. p1-3) were associated with RFS, while gender and pleural invasion were associated with OS. In SQ, however, smoking, clinical stage, and pulmonary metastasis were associated with RFS in the multivariate analysis. Conclusion: Since significant postoperative prognostic factors are quite different between lung AD and SQ, these two histologic types should be differently analyzed in a clinical study.