IARC Perspective on Oral Cancer Prevention

In 2020, cancer of the lip and oral cavity was estimated to rank 16th in incidence and mortality worldwide and was a common cause of cancer death in men across much of South and Southeast Asia and the Western Pacific. A wide range of genetic, environmental, and behavioral factors contribute to the risk of oral cancer. Risks are dominated by tobacco, both smoked and smokeless, and heavy alcohol consumption. In Southeast Asia and the Western Pacific Islands, where the incidence of oral cancer is high, the major risk factors are use of smokeless tobacco and areca nut products (including betel quid). A small percentage of oral cancer worldwide (approximately 2%) is caused by human papillomavirus infection, primarily HPV16.\nFrom September through December 2021, the International Agency for Research on Cancer (IARC) convened a working group of 25 scientists (all of whom are coauthors of this article) from 14 countries to evaluate the body of evidence on primary and secondary prevention of oral cancer. The working group reviewed all relevant published studies and evaluated the evidence according to the updated preambles of the IARC Handbooks of Cancer Prevention. The preambles describe the objectives and scope of the program, general principles and procedures, and scientific review and evaluations. In addition, to strengthen the current published evidence with respect to areca nut products, the working group performed primary analyses of unpublished data from large studies. Presented here is a brief overview of the studies that were reviewed and the outcomes of the evaluation process.