Comorbidity Assessment Using Charlson Comorbidity Index and Simplified Comorbidity Score and Its Association With Clinical Outcomes During First-Line Chemotherapy for Lung Cancer

The prevalence and association of comorbidity with clinical outcomes was assessed in a cohort of newly diagnosed lung cancer patients undergoing chemotherapy. Worse overall survival was independently associated with stage IV disease and poor performance status but not with Charlson Comorbidity Index (CCI) score or Simplified Comorbidity Score (SCS). CCI and SCS did not influence either radiological responses or toxicity. Background: Limited data is available on comorbidity assessment in patients with lung cancer. The present prospective study assessed the prevalence and association of the Charlson comorbidity index (CCI) and simplified comorbidity score (SCS) with clinical outcomes in patients with newly diagnosed lung cancer undergoing chemotherapy. Patients and Methods: All patients received histology-guided platinum doublets. The outcomes assessed were overall survival (OS), radiologic responses using Response Evaluation Criteria in Solid Tumors and toxicity using the Common Toxicity Criteria, version 3.0. The groups analyzed were SCS <= 9 (n = 173) and > 9 (n = 65) and CCI = 0 (n = 88), 1 (n = 97), and >= 2 (n = 53). Correlations of the CCI and SCS were assessed using Spearman's (rho) method. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated for the factors affecting OS using Cox proportional hazard (CPH) modeling. Results: Most patients had advanced disease (stage IIIB in 33.6%, stage IV in 42.4%). The median SCS was 7 (interquartile range, 7-11), and the median CCI was 1 (interquartile range, 0-1). The correlation between the CCI and SCS was moderate (rho = 0.474; P <.001). Age correlated weakly with both SCS (rho = 0.293; P <.001) and CCI (rho = 0.205; P < .001). The SCS > 9 group (vs. SCS >= 9) had a significantly older mean age, patients aged >= 70 years, men, smokers, and squamous cell histologic type. The mean age in the CCI groups was 55.2 years for a CCI of 0, 59.6 years for a CCI of 1, and 60.3 years for a CCI of 2, with a statistically significant difference (P = .002). The radiologic responses and toxicity profiles were similar between the SCS and CCI groups. The median OS was 287 days (95% CI, 232-342 days) and did not differ between the SCS and CCI groups. On multivariate CPH analyses, worse OS was independently associated with stage IV disease (adjusted HR, 2.0; 95% CI, 1.4-2.7) and poor performance status (Eastern Cooperative Oncology Group score >= 2; adjusted HR, 1.8; 95% CI, 1.1-2.8) but not with comorbidity, histologic type, or age. Conclusion: The SCS and CCI scores correlated moderately with each other and weakly with age. The presence of comorbidities did not adversely influence clinical outcomes in this Indian cohort of lung cancer patients undergoing first-line chemotherapy.