Adjuvant Chemotherapy Improves the Probability of Freedom From Recurrence in Patients With Resected Stage IB Lung Adenocarcinoma

Background. The benefit of adjuvant chemotherapy remains controversial for patients with stage IB non small-cell lung cancer (NSCLC). This study investigated the effect of adjuvant chemotherapy and the predictors of benefit from adjuvant chemotherapy in patients with stage IB lung adenocarcinoma. Methods. A total of 243 patients with completely resected pathologic stage IB lung adenocarcinoma were included in the study. Predictors of the benefits of improved overall survival (OS) or probability of freedom from recurrence (FFR) from platinum-based adjuvant chemotherapy in patients with resected stage IB lung adenocarcinoma were investigated. Results. Among the 243 patients, 70 (28.8%) had received platinum-based doublet adjuvant chemotherapy. A micropapillary/solid predominant pattern (versus an acinar/papillary predominant pattern) was a significantly worse prognostic factor for probability of FFR (p = 0.033). Although adjuvant chemotherapy (versus surgical intervention alone) was not a significant prognostic factor for OS (p = 0.303), it was a significant prognostic factor for a better probability of FFR (p = 0.029) on multivariate analysis. In propensity-score matched pairs, there was no significant difference in OS between patients who received adjuvant chemotherapy and those who did not (p = 0.386). Patients who received adjuvant chemotherapy had a significantly better probability of FFR than those who did not (p = 0.043). For patients with a predominantly micropapillary/solid pattern, adjuvant chemotherapy (p = 0.033) was a significant prognostic factor for a better probability of FFR on multivariate analysis. Conclusions. Adjuvant chemotherapy is a favorable prognostic factor for the probability of FFR in patients with stage IB lung adenocarcinoma, particularly in those with a micropapillary/solid predominant pattern. (C) 2016 by The Society of Thoracic Surgeons