Predicted Postoperative Lung Function is Associated with All-cause Long-term Mortality After Major Lung Resection for Cancer

Objectives: Preoperative lung function is an independent predictor of long-term survival after lung resection for non-small-cell lung cancer (NSCLC). The extent of resection has an impact on operative mortality, determines postoperative lung function and may influence both overall- and cancer-specific survival. We sought to determine the impact of predicted postoperative (ppo) lung function on long-term survival after lung cancer resection.

Methods: We previously reported long-term survival analyses for patients who underwent major lung resection for NSCLC 1980-2006. For this study, we calculated ppo spirometry (forced expiratory volume in the first second, FEV1) and diffusing capacity of the lung for carbon monoxide (DLCO) in the same cohort using the functional segment technique or quantitative perfusion scans when available, and updated survival data; missing data were imputed. We assessed the relationship of ppoFEV1 and ppoDLCO to long-term survival using Cox regression.

Results: Of 854 patients, 471 (55%) were men, the mean age was 63 years and median survival was 42 months. At the time of analysis, 70% of patients had died. On regression analysis, all-cause mortality was related to age, stage, performance status, renal function and prior myocardial infarction. Preoperative lung function was marginally associated with mortality [DLCO (10-percentage point decrease): HR (hazard ratio) 1.04, 95% confidence interval (95% CI) 1.00-1.08, P = 0.056; FEV1 (10-percentage point decrease): HR 1.04, 95% CI 1.00-1.09, P = 0.067]. In contrast, ppo lung function was strongly associated with mortality (ppoDLCO: HR 1.06, 95% CI 1.01-1.12, P = 0.024; ppoFEV1: HR 1.06, 95% CI 1.01-1.12, P = 0.031).

Conclusions: Ppo lung function is strongly associated with long-term survival after major lung resection and is more strongly related to survival than preoperative lung function. Surgeons struggle with challenging decisions about the appropriate extent of resection for early-stage cancer, balancing factors such as operative morbidity/mortality, local recurrence and postoperative quality of life. Ppo lung function and its relation to survival also should be taken into consideration during such deliberations.