HPV-Induced Oropharyngeal Squamous Cell Carcinomas in Brazil: Prevalence, Trend, Clinical, and Epidemiologic Characterization.

Background: Tobacco or human papillomavirus (HPV)-related oropharyngeal squamous cell carcinomas (OPSCC) represent different clinical and epidemiologic entities. This study investigated the prevalence of HPV-positive and HPV-negative OPSCC in a reference cancer hospital in Brazil and its association with clinical and demographic data, as well as its impact on overall survival. Methods: HPV infection was determined by p16-IHC in pre-treatment formalin-fixed paraffin-embedded samples from all patients with OPSCC diagnosed at Barretos Cancer Hospital between 2008 and 2018. The prevalence of HPV-positive cases and its temporal trend was assessed, and the association of clinical and demographic data with HPV infection and the impact on patient overall survival was evaluated. Results: A total of 797 patients with OPSCC were included in the study. The prevalence of HPV-associated tumors in the period was 20.6% [95% confidence interval, 17.5–24.0] with a significant trend for increase of HPV-positive cases over the years (annual percentage change = 12.87). In a multivariate analysis, the variables gender, level of education, smoking, tumor sublocation, region of Brazil, and tumor staging had a significant impact in HPV positivity, and a greater overall survival (OS) was observed in HPV-positive patients (5-year OS: 47.9% vs. 22.0%; P = 0.0001). Conclusions: This study represents the largest cohort of Brazilian patients with OPSCC characterized according to HPV status. We report significant differences in demographics and clinical presentation according to HPV status, and an increasing trend in prevalence for HPV-induced tumors. Impact: These findings can potentially contribute to a better stratification and management of patients as well as assist in prevention strategies.