Impact of COPD on pulmonary complications and on long-term survival of patients undergoing surgery for NSCLC

Abstract

Purpose: The purpose of our study was to determine the incidence of various types of postoperative pulmonary complications and to evaluate the impact of chronic obstructive pulmonary disease (COPD) on the long-term survival of patients with non-small cell lung cancer (NSCLC) undergoing pulmonary resection.

Methods: We performed a retrospective chart review of 244 patients who had undergone lung resection for NSCLC at Indiana University. COPD, defined as predicted forced expiratory volume in 1 s (FEV1)< or =70% and FEV1/FVC< or =70%, was determined based on preoperative pulmonary function testing in 78 of 244 patients (COPD group). The remaining 166 patients were classified as non-COPD. The incidence of postoperative complications, which included air leak of > or=10 days, atelectasis, pneumothorax, pneumonia, bronchopleural fistula, empyema, acute respiratory distress syndrome, mechanical ventilation of > or =7 days, and outpatient oxygen supplementation were compared between the two groups. Long-term survival and mortality due to respiratory failure were analyzed between the two groups using the Kaplan-Meier method and log rank test.

Results: All of the above-stated postoperative pulmonary complications occurred more frequently in the COPD than in the non-COPD patients (all P<0.01). The overall 5-year survival rate was 36.2% in the COPD and 41.2% in the non-COPD patients (P=0.1023). Five-year cancer related survival was 43.2% in the COPD and 47.7% in the non-COPD patients (P=0.357). There was no significant difference in survival among patients with different stages of lung cancer. However, the intercurrent survival, which is associated with non-cancer related death, was 60.1% in patients with COPD and 86.2% in patients without COPD at 5 years (P<0.0001). The major cause of non-cancer related death in the COPD group was respiratory failure (P=0.0008).

Conclusion: The presence of COPD is an acceptable predictor of postoperative pulmonary complications in patients with NSCLC. COPD is also a significant risk factor for development of respiratory-related complications, which may explain the poor long-term survival in these patients.