Objectives: Patients with non-small cell lung cancer (NSCLC) have a higher prevalence of co-morbidity associated with age and smoking. The aim of the current study is to test the prognostic value of pre-operative smoking cessation and co-morbidity.
Methods: Cigarette smoking status of 347 patients operated for NSCLC was determined based on two independent questionnaires taken prospectively prior to lung operation. The Charlson Co-morbidity Index (CCI) was calculated based on in-patients medical records. A Cox multiple regression model was used to test the prognostic value of smoking status and co-morbidity on survival together with other relevant factors.
Results: The distribution of co-morbidity was none (CCI = 0) in 123 (35.4%) patients; mild (CCI= 1-2) in 182(52.4%) patients; moderate (CCI= 3-4) in 37 (10.7%) patients; and severe (CCI≥ 5) in 5 (1.4%) patients. Older age was associated with higher CCI (p=0.001). Former smokers were significantly older (p<0.001) and had higher CCI (p=0.034). A multiple Cox regression analysis showed that older age (p<0.001), presence of lymph node metastases (p<0.001), pneumonectomy (p=0.013) and current smoking (p=0.006) were independent predictors of poor prognosis, while nonsmokers (relative risk=0.610, 95% confidence interval (C.I.)=0.350-1.061, p=0.080), former smokers (relative risk=0.633, 95% C.I.=0.458-0.877, p=0.006) and recent quitters (relative risk=0.573, 95% C.I.=0.362-0.908, p=0.018) had a significant better prognosis compared to current smokers. Co-morbidity had no prognostic value.
Conclusions: These results indicate that co-morbidity has no significant impact on overall survival and smoking cessation is beneficial and far more important for lung cancer patients at any time point prior to lung resection.