The fraction of cancer attributable to HPV is dominated by cervical cancer (83% of the 630,000 new cases of cancer per year worldwide). Three cancer sites in the head and neck (H&N) that are mainly due to tobacco and alcohol consumption have been also been associated with HPV: oropharynx (attributable fraction, AF= 13-60%, highest in Northern America and Europe) and, to a lesser extent, oral cavity and larynx (AF=1-4%).
Estimates of age (world) standardized incidence rates of HPV-associated cancer by country1. Comparison of HPV DNA prevalence in exfoliated cells from cancer-free tonsils and the oral cavity2.
Globally, around 30% of oropharyngeal cancers (OPC) are caused by HPV (29,000 cases per year). For cancers of the oral cavity, 4,400 cases per year are attributed to HPV and for larynx, 3,800 cases. Approximately 80% of cases of H&N cancer attributable to HPV occur in men and their geographical distribution is diametrically different from that of cervical cancer showing a much higher burden in high-income than low/middle income (LMICs) countries. Countries with relatively high incidence rates of HPV-attributable H&N cancer (over 1.25 per 100,000) are located in Northern America and Europe. The remaining H&N cancers are due to tobacco smoking or chewing and alcohol. By comparison, cervical cancer incidence rates vary from <10 per 100,000 in high-income countries to >50 per 100,000 in LMICs mainly due to differences in the population prevalence of cervical HPV infection and in cervical cancer screening provision. On account of a greater predominance of HPV16 compared to cervical cancer, HPV 16 and 18 are globally responsible for 85% H&N cancer (vs 71% in the cervix).
Among adults in France, HPV prevalence was 3.6% in tonsil brushings and 13.1% in gargles, and HPV16 prevalence was 2.2% and 4.1%, respectively. Percent agreement in HPV detection in paired tonsil brushings and gargles in adults was 85.8% and positive agreement 9.5%. HPV prevalence in gargles significantly varied by sex (prevalence ratio in men vs women=2.1; 95% confidence interval; 1.1-4.1).
HPV-attributable H&N cancer differs from cancer of the cervix to many extents: 1) much lower incidence rates; 2) male predominance; 3) unfavourable trends in AF and incidence rates in some high-income countries concomitant to increases in HPV infection and the decline in tobacco smoking and; 4) inadequacy of cytology- or HPV-based screening. Gargle is not representative of HPV prevalence in the tonsil. HPV vaccination has currently the greatest potential for prevention of HPV-induced OPCs while the cessation of tobacco use is essential to avoid other H&N cancers.
1. de Martel C, Plummer M, Vignat J, Franceschi S. Worldwide burden of cancer attributable to HPV by site, country and HPV type. Int J Cancer 2017;In Press.
2. Combes JD, Dalstein V, Gheit T, Clifford GM, Tommasino M, Clavel C, Lacau St Guily J, Franceschi S. Prevalence of human papillomavirus in tonsil brushings and gargles in cancer-free patients: The SPLIT study. Oral Oncol 2017;66: 52-7.