Impact of induction chemoradiotherapy on pulmonary function after lobectomy for lung cancer.

Objective: Our study aim was to determine whether there are differential changes in whole-lung and regional lung functions after lobectomy for lung cancer between propensity score-matched patients treated with and without induction chemoradiotherapy, by using single-photon emission computed tomography lung perfusion.

Methods: This study was a retrospective matched cohort study of consecutively acquired data. Pulmonary function test and perfusion scintigraphy were conducted before lobectomy and 6 months after lobectomy in patients treated with induction therapy (n = 72) and in those not treated (n = 170), for measuring functional changes of whole lung, contralateral lung, and lobes. After exact matching on resected lobe site, propensity scores for age, smoking status, preoperative pulmonary functions, and predicted postoperative pulmonary function were used to match the groups.

Results: After the matching, 46 patients were selected from the groups. Standardized mean differences of the 5 matched variables were <0.1. Whole lung function significantly decreased after lobectomy in the induction therapy group than in the noninduction therapy group (P < .001). Although ipsilateral preserved lobe function before surgery was not different between the groups (P = .33), postoperative value was significantly lower in the induction therapy group than in the noninduction therapy group (P < .001). Although both groups showed a significant increase of contralateral lung function after lobectomy (P < .01), the increases were not significantly different between the groups (P = .81).

Conclusions: Induction chemoradiotherapy was associated with reduced pulmonary function after lobectomy because of a decrease in ipsilateral preserved lobe function, which could be caused by the chronic effects of the induction chemoradiotherapy.