Could Tooth Decay Protect Against Cancer?
September 25, 2013
By Nancy Volkers
InteliHealth News Service
INTELIHEALTH - People with head and neck cancer have less tooth decay than people without the cancer, a study finds.
The study compared 399 people who had head and neck cancer with 221 who did not. All were adult patients at Roswell Park Cancer Institute in Buffalo, N.Y., between 1999 and 2007.
People with head and neck cancer tended to be:
Current or former smokers
Compared with the other group, those with head and neck cancer had:
Less tooth decay
Fewer root-canal treatments
More missing teeth
More bone loss in the jaw, which occurs when teeth fall out or are removed
Researchers took into account the differences between groups in sex, smoking status, alcohol use and age. These things might affect the risk of head and neck cancer.
They found that people with three or more decayed teeth had only about one-third the risk of head and neck cancer as those with no tooth decay. People with at least four crowns had about half the cancer risk of people with no crowns. And those who had at least two root canals also had about half the cancer risk of people who never had root canal treatment.
Tooth decay, or dental caries, is caused by bacteria. Other studies have shown that infection with decay-causing bacteria revs up part of the body's immune system. This type of immune-system activity is known to be linked with a decreased risk of cancer.
According to the American Cancer Society, about 53,600 cases of head and neck cancer will be diagnosed this year in the United States. Cases have increased steadily during the last several decades. Experts have pointed to infections with the human papillomavirus (HPV) as part of the reason. No other infection has been linked with head and neck cancer.
The study appears in the September 12 online edition of the journal JAMA Otolaryngology Head and Neck Surgery.