The Influence of Comorbidity and the Simplified Comorbidity Score on Overall Survival in Non–Small Cell Lung Cancer—A Prospective Cohort Study

Abstract

IntroductionWe addressed the uncertainty of comorbidity as a prognosticator by evaluating comorbidity and the Simplified Comorbidity Score (SCS) as predictors of overall survival in non–small cell lung cancer (NSCLC). MethodsA prospective study included patients in whom NSCLC was diagnosed at an Australian cancer hospital between 2012 and 2014. Patients were assessed for SCS at recruitment and followed up every 3 months until death. ResultsThe cohort included 633 patients; their median age was 67 years (range 28–93), 63% were male, and 86% were ever-smokers. The median SCS at enrolment was 8 (range 0–19); 20% had an SCS higher than 9, and 11% had an SCS of 0. An SCS higher than 9 was associated with male sex, age older than 75 years, an Eastern Cooperative Oncology Group performance status of 2 or higher, and fewer cancer treatments. The 1-year overall survival rate was 62% (95% confidence interval: 58–66). In multivariate analysis, the strongest associations with mortality were metastatic disease (hazard ratio [HR] = 2.8, p < 0.01), Eastern Cooperative Oncology Group performance status of 2 or higher (HR = 2.0, p < 0.01), male sex (HR = 1.6, p < 0.01), more than 10% weight loss at diagnosis (HR = 1.5, p < 0.01), and age older than 75 years (HR = 1.5, p = 0.01). An SCS higher than 9 was not associated with overall survival (HR = 1.0, p = 0.8), and the effect of continuous SCS (HR = 1.1, p < 0.01) was explained by smoking status. ConclusionsIn this cohort of patients with NSCLC the SCS was not a clinically significant predictor of overall survival over and above basic patient and disease factors.