Infection with Human Papilloma Virus (HPV) and risk of subsites within the oral cancer

Background: The aim of this study was to investigate the relationship between high-risk genotypes of Human Papilloma Virus (HPV) and cancer of different subsites of the oral cavity. Material and methods: A pooled analysis of five studies included on the International Head and Neck Cancer Epidemiology (INHANCE) Consortium was conducted. HPV 16 and HPV 18 were considered. Adjusted odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) for HPV and each oral cavity subsites were simultaneously estimated using multinomial logistic regression models. Results: The analysis included 1157 cases and 3272 controls. This study showed a slightly higher prevalence of HPV infection among oral cancer cases than controls. In particular, an increased risk of other and not otherwise specified (NOS) sites within the oral cavity, oral tongue, palate and floor of mouth cancer was observed for overall HPV16 positivity (OR = 1.66, 95 % CI: 1.01-2.72; OR = 1.97, 95 % CI: 1.36-2.85; OR = 2.48, 95 % CI: 1.50-4.11; OR = 2.71, 95 % CI: 1.06-6.95, respectively). In particular, HPV16E7 was related to cancer of floor of mouth, oral cavity NOS and palate (OR = 2.71, 95 % CI: 1.06-6.95; OR = 3.32, 95 % CI:1.53-7.19; OR = 3.34, 95 % CI:1.38-8.06). Results were inconsistent for HPV18 due to low prevalence of infection. Conclusion: Our study suggests that HPV16 infection may increase the risk of developing floor of mouth, gum, tongue, and palate cancers. Clinical relevance: Subjects with HPV infection have a higher risk of cancer from all sites of the oral cavity.