The changing epidemiology of oral cancer: definitions, trends, and risk factors.

Objective: This review has three objectives, namely: (i) to discuss how oral cancer is and ought to be defined and recorded; (ii) to present up-to-date data on the incidence burden of the disease in the four countries of the UK, and review recent analyses of trends in the disease; and (iii) to summarise recent evidence on risk factors of the disease. Methods: Cancer definitions were clarified by the International Classification of Diseases accounting for anatomical and aetiological differences; descriptive epidemiology included international / UK literature review and information requests for incidence data from the UK cancer registries (2000-2016); analytical epidemiology focused on reviewing the findings of the International Head and Neck Cancer Epidemiology (INHANCE) consortium, which has pooled data from multiple case-control studies providing the best estimates of risk factors. Results: Emerging evidence of the role played by risk factors in different anatomical sites means that oral cavity cancer and oropharynx cancer should be considered distinct disease entities ­ and a standardised attribution of anatomical subsites will be helpful in ensuring consistency in how data are presented. In 2016, over 3,700 people were diagnosed with oral cavity cancer and over 3,500 people were diagnosed with oropharyngeal cancer in the UK. Incidence of oropharyngeal cancer is rapidly rising across the UK. Rates of oral cavity cancer are higher in Northern Ireland and higher still (and relatively stable) in Scotland, but rising in England and Wales. INHANCE data show that while the consumption of alcohol and tobacco are the prime risk factors for oral cavity and oropharyngeal cancers, they provide greater certainty in the preventive benefits of reducing these risk factors. The role played by other factors such as low socioeconomic status, genetics, oral health, and human papillomavirus (only for oropharyngeal cancer) have become clearer. Conclusions: This epidemiology provides a strong foundation for designing and managing both population and individual oral cavity and oropharyngeal cancer control strategies.

Is detecting oral cancer in general dental practices a realistic expectation? A population-based study using population linked data in Scotland.

Aims: To examine, for the first time on a population-basis via data linkage, whether early detection by general dental practices (GDP) is a realistic expectation by i) estimating the number of OC cases/year a dentist in Scotland may encounter over time, accounting for the deprivation level of practice location and dental registration/attendance rates, and ii) assessing whether patients attended GDPs two years pre-diagnosis. Materials and methods: Scottish Cancer Registry data on all OC cases (2010-2012), published NHS Scotland dental workforce and registration/participation statistics, and individual patient data linked with NHS dental service activity were analysed. Results: Dentists were estimated to potentially encounter one case of OC every 10 years, OCC every 16.7 years, and OPC every 25 years. However, 53.7% of OC patients had made no dental contact two years pre-diagnosis. Conclusion: Strategies for early detection must consider the rarity of OC incidence and poor dental attendance patterns. These results highlight the importance of improving access and uptake of dental services among those at highest risk to increase the opportunities for early detection.