Harriet Rumgay of the International Agency for Research on Cancer (IARC) and colleagues from ten countries presented global epidemiological estimates for oral cancer, according to which almost a third of these tumors are caused by the use of smokeless tobacco products and chewing betel nut (Areca catechu) seeds. The researchers used data from national surveys on current consumption of such products, and the associated risks of oral cancer from the medical literature to calculate additional population risks. These were applied to national estimates of the incidence of such tumors from the Cancer Today database for 2022. The results are published in The Lancet Oncology.
In 2022, an estimated 390,000 cases of oral cancer were diagnosed worldwide. Of these, just over 120,000, or 30.8 (95% confidence interval 29.6–31.9) percent, were estimated to be associated with smokeless tobacco use and betel nut chewing. Men accounted for 77 percent of cases. Melanesia, Micronesia, and Polynesia, South Asia, and Southeast Asia were the regions with the highest incidence of smokeless tobacco and betel nut chewing. More than 108,000 cases, or 90.2 percent, occurred in lower-middle-income countries.