Approximately 4.5% of all cancers worldwide (630,000 new cancer cases per year of which 570,000 cases in women and 60,000 cases in men) are attributable to HPV1. Cancer risk and preventable fraction vary substantially by cancer site, sex, and age.
Comparison of the potential effectiveness of screening and vaccination approaches by cancer site and individual characteristics.
Of the six main cancer sites attributable to HPV, only for the cervix, and hence women, is screening recommended. Age is the only well-accepted criterion for screening eligibility. The typically recommended range is 25-64 years but it can be restricted, e.g., 30-49, to cope with resource limitations in low/middle income countries (LMICs), or expanded in some high-ICs with the aim of increasing women’s life expectancy. After the introduction of HPV testing, screening may be started later (30+ years) or stopped earlier thanks to anticipated diagnosis of precancerous lesions compared to cytology. Never-screened women will always be a priority. HIV infection and vaccination against HPV modulate screening intensity in opposite directions. Within screening, risk thresholds (benchmarks), based on HPV testing/genotyping, cytology, etc. are increasingly used in HICs to allow equal management of women for equal risk of CIN2+, irrespective of the screening tests. Only for anal cancer are lifestyle risk factors (men having sex with men and/or HIV+) very strong risk indicators. Even in high-risk men, however, anal cancer screening is however hampered by the low accuracy of HPV- and cytology-based risk stratification in anus. Worst of all, neither cytology2, nor non-invasive HPV testing (in oral cells3), allow screening for the relatively rare HPV-associated oropharyngeal cancer (80% in men). The detectability of oropharyngeal precancerous lesions is also uncertain. Finally, the efficacy of HPV vaccination to prevent vaccine-targeted HPV types and related lesions is best demonstrated in the female anogenital tract, but it is likely to apply to all HPV-related cancer sites in both sexes.
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. Franceschi S, Combes JD, Dalstein V, Caudroy S, Clifford G, Gheit T, Tommasino M, Clavel C, Lacau St Guily J, Birembaut P. Deep brush-based cytology in tonsils resected for benign diseases. Int J Cancer 2015;137: 2994-9.
3. 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.