Global trends for oral cancer have changed in many respects over the past 3 decades. Not only has the number of cases reported each year been rising in many countries, but the age standardised incidence has also increased in many parts of the globe. Taken together with oropharyngeal cancer, this is now the sixth most common cancer in the world. The Global Cancer Observatory (Globocan) has estimated that close to half a million people are affected each year and there are close to 150,000 deaths per annum. In addition to rising trends there are changes in demographic factors and the recognition of emerging risk factors. Oral cancer used to be a neoplasm that affected older people but more recent statistics from cancer registries worldwide indicate that 6–10% of cases diagnosed with oral cancer may be under the age of 45 years. Oral cancer has become a deadlier disease with about 50% dying with or from this disease within 5 years of diagnosis in most centres. This is largely due to late diagnosis resulting in treatment failure of oral cancer patients presenting in tertiary centres with advanced stages of disease. The Harvard Cancer Risk Index provides a broad classification of cancer risk for several major cancers. So far, approaches to develop risk models for oral cancer have been limited. This chapter examines methods of identifying people at high risk of developing oral cancer to set out a high-risk strategy to individualise approaches to early detection and prevention. Oral cancer is relatively common in South and East Asia and in some Pacific Islands in the continent of Oceania. According to Globocan, two-thirds of all oral cancers are reported from these regions of the world. In the Indian subcontinent, oral cancer could be the most common cancer in men and the third most common in women. The five countries with the highest ASRs in the world are Papua New Guinea, Taiwan, Maldives, Sri Lanka and Pakistan. The rates in these countries are 10–20 folds higher than countries with the lowest incidence and oral cancer is associated primarily with the betel quid chewing habit, referred to later in section “Areca Nut with Betel Quid”. Outside South Asia, oral cancer rates are also high among some parts of Western Europe (e.g., North West France and Portugal) and Eastern Europe (e.g., Hungary, Slovakia and Slovenia), parts of Latin America and the Caribbean (e.g., Brazil, Uruguay and Puerto Rico) and some former French colonies e.g., French–la Reunion. Thus any risk assessment for oral cancer should take into account the geographical location and lifestyles, and preventive and awareness programmes should be specifically directed to citizens from these nations.

White Caucasoid males in outdoor occupations exposed to UV light are at risk of lip cancer. Those who consume tobacco, excess alcohol or chew betel quid have an increased risk of tongue and oral cancer. Identifying at-risk individuals enables them to take appropriate steps to lower their risk of developing oral cancer. It is important to promote evidence-based cessation strategies to help smokers to quit tobacco use. Persistent HPV infection may lead to oropharyngeal cancer. Prediction of oral cancer risk is an important component of oral health risk appraisals in primary care. Detection of high-risk lesions that have the potential to transform to cancer provides opportunities to intervene. Stratification of OPMDs as “high risk” or “low risk” by chair-side adjunctive techniques and by cytology/histopathology needs to be tested in multicentre prospective studies. There are currently no models to predict an individual’s risk by combining various lifestyle risk factors and the presence or absence of an OPMD. The development of a risk prediction model would help to identify individuals that would benefit from oral cancer screening. There is an urgent need to develop evidence-based strategies to translate available knowledge to practice.  Future research should attempt to identify novel biomarkers in order to identify those at risk.

Regards
Sarah eve
Editorial Assistant
Journal of Oral Hygiene and Health