HPV and Other Risk Factors: Oropharyngeal Tumor Survival

Abstract

Objective: Oropharyngeal carcinomas are associated with tobacco smoking and alcohol but also HPV infection. HPVassociated carcinomas have a more favorable prognosis in contrast to tobacco- and alcohol-induced carcinomas. Frequency and outcome of HPV-associated oropharyngeal carcinomas (tonsils and base of tongue) in a cohort with high prevalence of smoking are reported. Method: A group of 114 patients with oropharyngeal squamous cell carcinomas (60 tonsil tumors, 54 base of tongue tumors) was controlled. Surgery, chemoradiation, or radiotherapy was performed according to the stage of disease. Complete follow-up was obtained in fall 2010. Histologic slides were retrieved and stained for p16 as HPV association indicator. Results: All 114 patients (81% smokers, 64% tumors stained positive for p16, tonsils 73%, base of tongue 54%). With a median follow-up of 28 months, 31 patients had disease progression and 39 patients died. Three-year PFS rates were 79% and 52% in patients with p16+ vs p16- tumors (P = .001 by log-rank test). In Cox regression analysis, only stage and p16 were independent prognostic factors. For PFS p16 had a hazard ratio (HR) of 0.44% (95% CI, 0.25 to 0.78). Conclusion: Even in a European population with high prevalence of tobacco smoking, p16 positivity remains a strong favorable and independent risk factor, as has previously been shown in US cohorts with far lower smoking prevalence.