Prevalence, Morphology, and Prognosis of Human Papillomavirus in Tonsillar Cancer

OBJECTIVES: We sought to identify the prevalence of human papillomavirus (HPV) in tonsillar squamous cell carcinoma, and to examine the relationship of HPV to prognosis and tumor morphology. METHODS: We performed in situ hybridization for HPV and retrospective clinical outcome analysis. RESULTS: Of the 48 patients with tonsillar carcinoma, in situ hybridization identified 35% as HPV-positive tumors. Age-matched controls had no evidence of HPV. There was no significant difference between HPV-positive and HPV-negative patients regarding age (p = 0.34), tobacco consumption (p = 0.59), alcohol consumption (p = 0.91), or treatment method (p = 0.39). Forty-four patients were eligible for outcome analysis. The overall rate of recurrence in this population was 25%, and the disease-specific survival rate was 84%. There was no significant difference between the two groups either in the incidence of recurrence (p = 0.14) or in the disease-specific survival rate (p = 0.19). HPV-associated tumors developed from the tonsillar crypts significantly more frequently than did HPV-negative tumors (p = 0.01). CONCLUSIONS: As previously described, HPV is significantly associated with squamous cell carcinoma of the tonsil; however, HPV status in our series did not correlate with clinical outcome. Morphologically, we found that HPV-positive tumors had their origin in the tonsillar crypts, whereas HPV-negative tumors arose from the surface epithelium.