Introduction: Upper aero-digestive tract cancer is a multidimensional problem, international trends showing
complex rises and falls in incidence and mortality across the globe, with variation across different cultural and
socio-economic groups. This paper seeks some explanations and identifies some research and policy needs.
Methodological Approach: The literature illustrates the multifactorial nature of carcinogenesis. At the cellular
level, it is viewed as a multistep process involving multiple mutations and selection for cells with progressively
increasing capacity for proliferation, survival, invasion, and metastasis. Established and emerging risk factors,
in addition to changes in incidence and prevalence of cancers of the upper aero-digestive tract, were identified.
Risk Factors: Exposure to tobacco and alcohol, as well as diets inadequate in fresh fruits and vegetables,
remain the major risk factors, with persistent infection by particular so-called “high risk” genotypes of human
papillomavirus increasingly recognised as also playing an important role in a subset of cases, particularly for
the oropharynx. Chronic trauma to oral mucosa from poor restorations and prostheses, in addition to poor
oral hygiene with a consequent heavy microbial load in the mouth, are also emerging as significant risk factors.
Conclusions: Understanding and quantifying the impact of individual risk factors for these cancers is vital for
health decision-making, planning and prevention. National policies and programmes should be designed and
implemented to control exposure to environmental risks, by legislation if necessary, and to raise awareness so
that people are provided with the information and support they need to adopt healthy lifestyles.