Abstract
BACKGROUND: The impact of impaired pulmonary function on the clinical outcome of small cell lung cancer (SCLC) has not been examined. The objectives of this study were to compare the clinical characteristics and prognosis of SCLC patients with and without impaired pulmonary function and investigate predictors related to the pulmonary function of mortality in SCLC patients. METHODS: This is a retrospective multicenter study performed between January 2011 and December 2015. In all, 170 SCLC patients that were treated with chemotherapy and/or radiotherapy and had a pulmonary function test (PFT) were enrolled. Patients were divided into the chronic obstructive pulmonary disease (COPD) group and the non-COPD group. The overall survival (OS) was compared and predictors of worse OS were analyzed. RESULTS: COPD was present in 54.7% of all SCLC patients. There were no differences in the clinical characteristics and treatment strategies between the COPD and non-COPD groups. OS (log-rank test, P=0.103) was not different between the COPD and non-COPD groups. In a multivariate analysis using a Cox regression model, extensive disease (ED) [hazard ratio (HR) =2.863; 95% CI: 1.787-4.587] and low forced expiratory volume in 1 second (FEV(1)) <80% (HR =1.854; 95% CI: 1.077-3.192) were independent risk factors for shorter survival. In a subgroup multivariate analysis, a FEV(1) less than 80% (HR =5.631; P=0.018) was independently associated with poor OS in patients with ED. CONCLUSIONS: A low FEV(1), not COPD, was a predicting factor for poor treatment outcomes in SCLC patients.