The impact of comorbidity on overall survival in elderly nasopharyngeal carcinoma patients: a National Cancer Data Base analysis

The number of elderly patients with cancer is increasing. Medical comorbidities are more common in this population. Little is known regarding the prognostic relevance of comorbidities in elderly patients with nasopharyngeal carcinoma (NPC). Using the National Cancer Data Base (NCDB), we queried patients age >65 years diagnosed with NPC and treated with definitive radiation between 2004 and 2012 to examine the association between comorbidity and survival outcomes. Comorbidity was assessed with the Charlson Comorbidity Index (CCI). The influence of comorbidity on overall survival (OS) was evaluated. Cox proportional hazards model was used to study the impact of comorbidity on OS. A total of 1137 patients met the specified criteria. Median follow-up was 61.2 months. Five-year OS was 50.4%. Comorbidities were present in 22.4% of patients, with 17.6% of patients having a CCI score of 1% and 4.8% having a CCI score of >= 2. Patients with a CCI score of 0 had significantly higher 5-year OS than patients with a CCI score of 1 or >= 2 (53.1% vs. 42.2% vs. 32.9%, P < 0.001). In multivariate analysis, CCI was a statistically significant independent prognostic factor for the risk of death of all causes for patients with a CCI score of 1 (hazard ratio [HR]: 1.242; 95% confidence interval [CI]: 1.002-1.539) or CCI score of >= 2 (HR: 1.625; 95% CI: 1.157-2.283) when compared to patients with a CCI score of 0. Comorbidity as measured by CCI is a strong independent prognostic factor for OS in elderly patients with NPC and lends support to the inclusion of comorbidity assessment due to its prognostic value when treating elderly patients with NPC.