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As with lung cancer,
many etiologic agents and risk factors have been associated with head
and neck cancer. While evidence
for some of them may not be very strong, the risk of developing an oral,
pharyngeal or laryngeal cancer increases linearly with tobacco and
alcohol consumption.
Numerous studies have
concluded that tobacco, which contains carcinogens such as polonium 210,
nitrosamines, and aromatic hydrocarbons, is directly linked to
development of carcinomas.
More than 90 percent
of oropharyngeal cancers are associated with smoking.
Alcohol has a strong
association with head and neck cancer as well, especially when a user
also smokes or chews tobacco.
Although alcohol itself is not a carcinogen, it promotes the
carcinogenicity of tobacco.
Various chemicals have
been associated with head and neck cancer, including asbestos, chromium,
nickel, arsenic and formaldehyde.
Whether asbestos is a risk factor for head and neck cancer is
controversial. While it is a
strong risk factor for lung cancer, some studies have found no increased
risk of head and neck cancers among asbestos workers.
Other factors in head
and neck cancer include ionizing radiation, Plummer-Vinson Syndrome,
Epstein-Barr Virus and Human Papilloma Virus.
Plummer-Vinson Syndrome is rare, but these patients definitely
have a high incidence of hypopharyngeal cancer.
Though a cause-and-effect relationship has not been established,
Human Papilloma Virus DNA has been isolated from head and neck cancer as
well as from cancers of the uterine cervix in females.
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