Prevalence of human papillomavirus types and variants and p16(INK4a) expression in head and neck squamous cells carcinomas in Sao Paulo, Brazil

Background Human papillomavirus (HPV) prevalence in head and neck squamous cell carcinomas (HNSCC) diverges geographically. The reliability of using p16INK4a expression as a marker of viral infection is controversial in HNSCC. We evaluated HPV types and HPV-16 variants prevalence, and p16INK4a expression in HNSCC specimens provided by two different Institutions in Sao Paulo.