Predictors of long‐term compensatory response of pulmonary function following major lung resection for non‐small cell lung cancer

Background and objective Long‐term pulmonary function which might include compensatory response ( CR ) significantly influences quality of life of long‐term survivor after major lung resection. We investigated long‐term pulmonary function after major lung resection. Methods A total of 137 patients who had undergone lobar resection for non‐small cell lung cancer ( NSCLC ) from May 2013 to June 2014 had spirometry at 10–14 months after surgery. Actual post‐operative forced expiratory volume in 1 s ( FEV 1 ) ( FEV 1apo )/predicted post‐operative FEV 1 ( FEV 1ppo ), actual post‐operative forced vital capacity ( FVC ) ( FVC apo )/predicted post‐operative FVC ( FVC ppo ), its relationship with clinicopathological factors and immunohistochemistry for pro‐surfactant protein C (pro‐ SPC ), thyroid transcription factor‐1 ( TTF ‐1) and vascular endothelial growth factor receptor 2 ( VEGFR2 ) were investigated. Results FEV 1apo / FEV 1ppo showed strong correlation with FVC apo / FVC ppo (r = 0.628; P < 0.001). We defined greater CR as both FEV 1apo / FEV 1ppo and FVC apo / FVC ppo were >120%. Greater CR was significantly associated with decreased smoking index ( P < 0.001) and greater resected subsegments ( P = 0.037). The never‐smoker group revealed significantly greater CR compared with the smoker group in both FEV 1apo / FEV 1ppo (119.9 ± 12.5% vs 107.5 ± 14.2%; P = 0.030) and FVC apo / FVC ppo (117.9 ± 9.98% vs 107.2 ± 13.1%; P = 0.046) in case‐matched comparison. The expression of pro‐ SPC , TTF ‐1 and VEGFR2 in the normal lung parenchyma of greater CR group was significantly higher than those of lesser CR group ( P < 0.001 for each). In addition, pro‐ SPC , TTF ‐1 and VEGFR2 expressions showed a significant correlation to the degree of CR especially in the smoker group (r = 0.631, 0.705 and 0.732, respectively; P < 0.001 for each). Conclusion Our data suggest that smokers may develop lesser long‐term CR after major lung resection. Decreased expression of pro‐ SPC , TTF ‐1 and VEGFR2 may indicate decreased capacity of CR , especially in patients who smoke.