Carvalho RS, Scapulatempo-Neto C, Curado P, et al. - Studies have described differences in clinical as well as epidemiological aspects of tobacco or human papillomavirus (HPV)-related oropharyngeal squamous cell carcinomas (OPSCC). In this study, the prevalence of HPV-positive and HPV-negative OPSCC was examined in a reference cancer hospital in Brazil and its correlation with clinical and demographic data, as well as its impact on overall survival, was determined. In this largest cohort of Brazilian OPSCC patients characterized according to HPV status, a total of 797 OPSCC patients were included. HPV-associated tumors were prevalent in 20.6% with a significant trend for increase of HPV-positive cases over the years. In a multivariate analysis, the following variables were noted to have a significant impact in HPV positivity: gender, level of education, smoking, tumor sub-location, region of Brazil and tumor staging; a greater overall survival (OS) was recorded in HPV-positive patients.