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The major risk
factors for oral cancers are tobacco and alcohol use. Tobacco contains
carcinogenic substances as well as substances that act as initiators
or promoters of carcinogenesis. The most harmful carcinogens are
found in the tars of tobacco smoke, but many forms of smokeless
or "spit" tobacco have been associated with the development
of oral cancer.
The role of
alcohol in oral cancer appears to be related to its damaging effect
on the liver. Major metabolites of alcohol, such as acetaldehyde
'a known carcinogen in animals' may also be important. Alcohol is
also thought to act as a solvent that facilitates the entry of tobacco
carcinogens into oral tissues.
This may partly
explain why the combined use of tobacco and alcohol produces a greater
risk for oral cancer than use of either substance alone. Indeed,
tobacco and alcohol, working in tandem, are thought to account for
75 to 90 percent of all oral and pharyngeal cancers in the United
States . For information on how to counsel patients about tobacco
cessation, please refer to Tobacco
cessation.
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