About the HPV-AHEAD Consortium
Rationale and Background Information
Head and Neck Cancer (HNC) is the sixth most common malignancy reported worldwide and one with a high case fatality rate, with an estimated global burden of approximately 550,000 incident cases and 300,000 deaths per year. Approximately 50% of HNC are in the oral cavity, followed by 30% in the larynx and 10% in the oropharynx. Alcohol consumption, smoking, poor oral hygiene and genetic features are key risk factors for HNC development. In addition, in the last decade it has become clear that a sub-set of HNC covering approximately 25% of the worldwide cases is associated with certain HPV types, referred to as high-risk (HR) HPV types. The group of HR HPVs comprises approximately 15 different types, which are associated with cancers of the genital tract. HPV16 is the most carcinogenic type in the HR HPV group, responsible of approximately 50% of cervical cancers worldwide. In HNC, the majority of the HPV-associated cases (between 86-95%) are associated with HPV16, while the remaining HR HPV types appear to play only a marginal role. Among the different types of HNC, oropharyngeal carcinomas are the most frequently HPV-associated, while HPV prevalence in cancers of the oral cavity, larynx and hypopharynx appears to be considerably lower.
Although the overall incidence of HNC is decreasing in western countries due to the awareness of the adverse effects of tobacco in human carcinogenesis, the percentage of oropharyngeal cancers is steadily increasing in certain regions of USA and Europe, but whether this phenomenon is linked to an increase of HPV infection and/or other factors remains to be proven. Additional studies are needed to confirm the increasing importance of HPV infection in HNC development in European populations. The Indian sub-continent has the highest HNC incidence in the world, and it accounts for one-third of the world burden. HNC accounts for approximately 30-40% of all cancer types in India. Many etiological factors are involved in HNC development in the Indian population, including alcohol and smoking. The habit of chewing betel quid often mixed with tobacco is widespread in South-East Asia, and also plays a key role in HNC development. India, with an age-standardized incidence rate of 22, is among the countries with the highest incidence of cervical cancer worldwide. However, only a few studies have analyzed the presence of HPV infection in HNC in the Indian population. Although the initial data indicate that also in India HPV infection plays a key role in HNC, more investigations are required to elucidate the importance of HPV infection alone or in combination with other risk factors in HNC in different Indian regions with different HNC incidence.