Competing causes of death and medical comorbidities among patients with human papillomavirus-positive vs human papillomavirus-negative oropharyngeal carcinoma and impact on adherence to radiotherapy

IMPORTANCE: Survival of patients with head and neck cancer can be affected by competing causes of mortality, as well as comorbidities that result in radiation treatment interruptions. OBJECTIVE: To discern how differences in preexisting medical and psychosocial comorbidities potentially influence adherence to radiation therapy according to human papillomavirus (HPV) status. DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis at a comprehensive cancer center of 162 consecutive patients with locally advanced squamous cell carcinoma of the oropharynx treated with primary chemoradiation (n = 95) or primary surgery followed by adjuvant radiation (n = 67). Immunostaining for p16 was used to determine HPV status. MAIN OUTCOMES AND MEASURES: Difference in alcohol, tobacco, and marijuana usewas compared between patients with HPV-positive and HPV-negative tumors, as well as the prevalence of the following comorbidities: diabetes mellitus, chronic obstructive pulmonary disease (COPD), anxiety disorder, and major depression. The number of total missed treatment days was analyzed as both a continuous and categorical variable. RESULTS: Rates of self-reported heavy alcohol use (47%vs 16%; P = .02) and any marijuana use (47%vs 23%; P = .003) were significantly higher among HPV-negative patients. Fifty-four percent of HPV-positive patients self-identified as never smokers, compared with only 12%of HPV-negative patients (P < .001). HPV-negative patients had more missed treatment days (mean, 2.8 vs 1.7 days; P = .02), as well as an increased rate of at least 5 missed days (24%vs 10%; P = .04), and higher prevalences of COPD (12%vs 7%; P = .37) and anxiety disorder (12%vs 6%; P = .35). CONCLUSIONS AND RELEVANCE: Pronounced differences exist in lifestyle habits between patients with HPV-negative and HPV-positive oropharyngeal cancer at diagnosis. These differences, as well as those of medical and psychosocial burden, may contribute to observed discrepancies in treatment adherence and need to be considered in outcomes reporting and clinical trial design.