Influence of Postoperative Infectious Complications on Long-Term Survival of Lung Cancer Patients: A Population-Based Cohort Study

Introduction: Surgery is essential to any curative plan for lung cancer, but is associated with a high complication rate. We sought to determine the impact of complications on long-term survival after a curative surgery for lung cancer, independent of the effect on early postoperative mortality. Methods: We studied a population-based cohort of patients with lung cancer who underwent curative-intent surgery in the province of Quebec, Canada, from 2000 to 2005. Kaplan-Meier survival analysis was used to compare unadjusted overall survival (OS) beyond postoperative day 90 for patients with and without complications. Cox regression was used to determine the prognostic impact of 30-day postoperative complications on the OS after adjusting for several confounders. Results: The overall 30-day postoperative complication rate was 58.2% among 4033 eligible patients. A major infectious complication (pneumonia, empyema, or mediastinitis) occurred in 378 patients. The 5-year OS was lower for those with any postoperative complication (62.8%) than those without (73.8%; p < 0.001). Those with major infectious complications had the lowest OS (56.3%; p < 0.001). Postoperative complication was an independent prognostic factor after adjusting for several patient and treatment factors (hazard ratio = 1.37; 95% confidence interval, 1.21-1.54). Adjusted hazard ratio for major infectious complications was 1.67 (95% confidence interval, 1.39-2.01). Conclusions: Postoperative complications, particularly of a major infectious type, are strong negative predictors of long-term survival in lung cancer patients. The strong association between major infectious complications and survival may also open the door to investigational therapies targeting bacterial antigens in the perioperative period in patients who undergo lung cancer surgery.