Comorbidity and prognosis in head and neck cancers: Differences by subsite, stage, and human papillomavirus status.

BACKGROUND The prognostic utility of comorbidity on head and neck cancer may differ by subsite, stage, and human papillomavirus (HPV) status. METHODS We reviewed the medical records of 4953 patients with head and neck cancer for comorbidity (Charlson Comorbidity Index [CCI]), smoking, and alcohol history. Multivariate proportional hazards assessed the association of CCI with survival. HPV status was determined using p16 immunohistochemistry. RESULTS After accounting for stage, higher CCI was associated with worse overall survival (OS) in nasopharyngeal (hazard ratio [HR], 2.93; 95% confidence interval [CI], 1.53-5.62), oropharyngeal (HR, 1.99; 95% CI, 1.63-2.43), and oral cavity cancers (HR, 1.54; 95% CI, 1.27-1.86). These associations were most prominent in the early stage oral cavity (HR, 2.11; 95% CI, 1.50-2.96) and laryngeal (HR, 1.87; 95% CI, 1.35-2.58) cancers, and in advanced stage oropharyngeal (HR, 2.23; 95% CI, 1.81-2.74) and nasopharyngeal (HR, 3.50; 95% CI, 1.76-6.97) cancers. CCI was independently prognostic even in the HPV-adjusted oropharyngeal cancers. CONCLUSION Comorbidity was prognostic in subsets of nasopharyngeal, oropharyngeal, oral cavity, and laryngeal cancers. Comorbidity may be a partial surrogate for age and social habits.