The Prognostic Role of Chronic Obstructive Pulmonary Disease for Lung Cancer After Pulmonary Resection.

INTRODUCTION: Surgery offers the best potential cure for patients with lung cancer; however, whether the coexistence of chronic obstructive pulmonary disease (COPD) with lung cancer affects the prognosis of such patients after surgical resection remains unclear. This systematic review and meta-analysis aimed to determine the effect of coexisting COPD on the overall survival and postoperative complications in patients with lung cancer who have undergone surgical resection. METHODS: A systematic electronic search was performed on the PubMed, Embase, and Cochrane Library databases to identify relevant studies published since the inception of these databases until November 2020. The hazard ratio and odds ratio (OR) with 95% confidence intervals (CIs) were used to assess the effect estimates of the relative risk for the role of COPD; the pooled outcomes were calculated using the random-effects model. RESULTS: Nineteen studies (two prospective and 17 retrospective studies) involving 14,171 patients with lung cancer (4975 patients with coexisting COPD) who had previously undergone surgical resection were selected for the final meta-analysis. We found an association between the presence of COPD in patients with lung cancer and poor overall survival (hazard ratio: 1.37; 95% CI: 1.22-1.55; P < 0.001). Moreover, patients with COPD had a higher risk of bronchopleural fistula (OR: 1.82; 95% CI: 1.17-2.81; P = 0.008), pneumonia (OR: 3.64; 95% CI: 2.61-5.07; P < 0.001), prolonged air leakage (OR: 2.77; 95% CI: 1.30-5.90; P = 0.008), and prolonged mechanical ventilation (OR: 2.15; 95% CI: 1.28-3.60; P = 0.004). However, the presence of COPD was not associated with the risk of empyema (OR: 1.46; 95% CI: 0.68-3.13; P = 0.332). CONCLUSIONS: This study showed that coexisting COPD in patients with lung cancer who had undergone surgical resection was associated with a poor prognosis. This conclusion should be interpreted cautiously because most of the included studies were retrospective in nature.