Long-term pulmonary function after lobectomy for primary lung cancer.

The aim of this study was to investigate the factors affecting long-term postoperative pulmonary function with a view to increasing the application of combined resection, bronchoplasty, and induction therapy. Results in 80 patients who underwent lobectomy for primary lung cancer were analyzed. Predicted postoperative pulmonary function was calculated using the formula: postoperative predicted function=preoperative function x[1-(b-n)/(42-n)], where n and b are the numbers of obstructed segments and total segments, respectively, in the resected lobe. Spirometry was performed serially on the preoperative day, and at 3, 6, 12, 18, and 24 months postoperatively. The difference between the predicted postoperative pulmonary function and the function measured at 12 months postoperatively was calculated, and clinical and therapeutic variables were analyzed. Univariate analysis revealed that the difference in vital capacity was significantly related to surgical approach, bronchoplasty, and induction therapy, while the difference in forced expiratory volume in one second (FEV1) correlated with surgical approach and induction therapy. Multiple regression analysis showed induction therapy to be the sole factor related to the differences in both vital capacity and FEV1. Lung resection after induction therapy may cause an additional loss of pulmonary function in the late phase.