In 1859, a french doctor noted that 67 of 68 oral cancer patients were:

Smokers

The use of tobacco, usually in the form of cigarettes, chewing tobacco or snuff, has been linked to increase the risks of most cancers, including oral cancers, because of the chemicals present in the tobacco that may cause cancer. The risk of developing oral cancer from tobacco use depends on the frequency and the length of time of the use. Smoking can lead to mouth or throat cancers and oral tobacco use in general are also associated with cancers in the mouth as well.