As a practicing oral and maxillofacial pathologist for over 25 years in the Southeast U.S. – also known as Smokeless Tobacco Country – I diagnosed over a thousand mouth cancers in smokers and heavy drinkers, but few in nonsmokers who used moist snuff or chewing tobacco. Large epidemiologic studies conducted over the past 40 years confirm the much higher mouth cancer risk posed by cigarettes versus smoke-free products (here and here).
Recognizing the public health impact of this data, I have given hundreds of lectures to dentists and other health professionals about the benefits of switching inveterate smokers to safer smoke-free tobacco – a scientifically validated form of harm reduction. On occasion, I am confronted by a dentist who insists that they have seen in their practice many oral cancers caused by smokeless tobacco. Given that smokeless tobacco users’ cancer risks are no higher than those of nonusers (discussed here and here), the possibility of a dentist seeing numerous smokeless-related cancers is remote. A dentist in Oklahoma recently made that claim to one of my tobacco harm reduction colleagues.
To test the validity of that claim, we can focus on data involving men age 45 and older, as smokeless tobacco use among women is rare. Incidence (new case) rates for mouth cancer in Oklahoma are unknown, but CDC data reveals (here) that the death rate from mouth cancer among men in Oklahoma is about 11% higher than the U.S. rate. From that, we can assume that the Oklahoma incidence rate is also 11% higher.
According to the Surveillance, Epidemiology and End Results (SEER) program at the National Cancer Institute (here), the national incidence rate for mouth cancer is 23 cases per 100,000 men age 45+ years per year. With census data showing there are 716,468 men age 45+ years in Oklahoma, applying the 11% adjustment we can extrapolate that there are 183 cases of mouth cancer in Oklahoma annually.
If every case of mouth cancer in Oklahoma was diagnosed by the state’s 2038 dentists (here) – and that is highly unlikely – on average, each dentist would see one case every 11 years. (This estimate is similar to one we provided in a research article in 2007 -- abstract here). Some dentists might see an unusually large number of smokers and heavy drinkers in their practice, so they might see a few more mouth cancers. But their totals would still be minuscule.
The fact is, dentists and other general health professionals do not see high numbers of dippers and chewers with mouth cancer.