If you needed another reason to quit smoking, there you have it. Medical researchers found a link between smoking and mouth cancer developed after getting infected with human papillomavirus type 16 (HPV16). Even three cigarettes a day increase the risks of catching the virus by one-third, according to researchers at John Hopkins University.
Oral sex is the main mode that HPV16 gets transmitted. The virus is responsible for 80 percent of the cancers developed in the back of the throat. This type of cancer develops more often, as in the last 20 years the rate increased by 225 percent.
“The practice of oral sex is common, but this cancer is rare,” says study author Gypsyamber D’Souza. “So there must be cofactors in the process that explain why some people develop persistent HPV16 infections and HPV-positive oropharyngeal cancers when most other people don’t.”
Researchers looked at data from 7,000 people who were interviewed during the U.S. National Health and Nutrition Examination Survey. Only 2,000 of them were tobacco consumers, 80 percent as cigarette smokers and the rest as pipe smokers and tobacco chewers. The nicotine levels in the tobacco consumer’s blood indicated elevated risks of contracting HPV16.
Smoking or other types of tobacco consumption do not increase the risk of getting infected with HPV16, by themselves, but researchers discovered a link between the two. Second hand smokers show similar characteristics.
There is one reason why researchers have troubles in establishing a direct causation between smoking and the infection with HPV16.
“We don’t fully understand oral HPV16,” said Dr. Carole Fakhry, assistant professor of otolaryngology-head and neck surgery at Johns Hopkins University School of Medicine. “People exposed to tobacco could be more likely to become infected after exposure to HPV16 or less likely to get rid of the infection.”
Fortunately, infection with oral HPV16 is not common. If you have the virus, it does not automatically mean that you will develop cancer. Researchers are trying to understand how the two variables interact. One hypothesis would be that tobacco weakens the immune system. Consequently, the body faces difficulties when fighting the infection.
Even when sexual behavior was taken into account, the results showed clearly that tobacco plays a part in the process.
Around 37,000 Americans are expected to develop mouth or throat cancer this year. The American Cancer Society says that around 7,300 are expected to die because of it.