Charlson Comorbidity Index predicts patient outcome, in cases of inoperable non-small cell lung cancer treated with radiofrequency ablation.

Simon, Tracey G; Beland, Michael D; Machan, Jason T; Dipetrillo, Thomas; Dupuy, Damian E

PURPOSE The Charlson Comorbidity Index (CCI) has been shown to be a significant prognostic indicator in the treatment of many types of cancer. The aim of this study is to evaluate the degree to which the CCI predicts survival in patients with inoperable non-small cell lung cancer (NSCLC) treated with radiofrequency ablation (RFA). MATERIALS AND METHODS Eighty-two (34 men, 48 women) consecutive RFA treatments for medically inoperable NSCLC were performed at our institution from 1/1/2000 to 1/30/2009. With institutional IRB approval and in full HIPAA compliance, the medical records of these patients were examined for data relating to pre-treatment comorbid conditions, and a retrospective analysis was conducted. Survival curves were estimated by the Kaplan-Meier method. Risk factors for mortality were determined by single-factor comparisons of curves using Wilcoxon-weighted chi-square and multiple Cox regressions. RESULTS The patients ranged in age from 59 to 91 years (mean: 75.5). Eighty-eight percent (72 patients) were tumor stage IA or IB. Patients were followed for a total of five years; three-year overall survival was 50.6%. Hospital mortality was 0%. Gender, stage, histology and CCI score were each associated with significantly impaired survival (p<0.001 in all cases). After covarying for age, tumor stage>IB, squamous histology and gender, multiple Cox regressions showed that an increasing CCI score was significantly associated with an increased risk of death (HR 1.3, 95% CI 25.5, 58.2). CONCLUSIONS The CCI is validated as an important, independent predictor of patient survival, in cases of inoperable NSCLC treated with RFA.