The incidence and impact of comorbidity diagnosed after the onset of head and neck cancer.

OBJECTIVE: To investigate the incidence and prognostic impact of comorbidities diagnosed after the onset of head and neck cancer.
DESIGN: Retrospective review of medical records. PATIENTS: One hundred eighty-three patients diagnosed as having head and neck cancer at Washington University School of Medicine from January 1, 1997, through December 31, 1998. MAIN OUTCOME MEASURES: We reviewed medical records for demographic, tumor, treatment, and comorbidity data. Comorbid ailments at diagnosis and last follow-up or death were coded using the Adult Comorbidity Evaluation-27.
RESULTS: Of the 183 patients, 53 (29.0%) were found to have a baseline comorbidity score of none; 58 (32.0%) of mild; 53 (29.0%) of moderate; and 19 (10.4%) of severe. At last follow-up or death, scores were none for 30 patients (16.4%), mild for 52 (28.4%), moderate for 43 (23.5%), and severe for 58 (31.7%). Comorbidity scores at baseline (P = .002) and last follow-up (P = .001) were associated with 5-year survival. The prognostic impact of comorbidity scores at baseline and last follow-up were analyzed using Cox proportional hazards analysis. Individual comorbid ailments after diagnosis included myocardial infarction, coronary artery disease/angina, solid tumor, psychiatric disease, chronic obstructive pulmonary disease, hypertension, and alcohol abuse.
CONCLUSIONS: These findings are consistent with previous research demonstrating that comorbidity at diagnosis is strongly correlated with prognosis. This study also showed that the burden of comorbidity changes after diagnosis. There appeared to be a prognostic gradient based on comorbidity severity at baseline and outcome despite adjusting for age, sex, and cancer stage. Additional studies with larger numbers of patients and longer follow-up should be performed to investigate the importance of comorbidities that arise after diagnosis and may be a result of treatment.