Human papillomavirus (HPV) infection
Human papillomavirus (HPV) is a group of more than 150 types of viruses. They are called papillomaviruses because some of them cause a type of growth called a papilloma. Papillomas are not cancers, and are more commonly called warts.
Infection with certain types of HPV can also cause some forms of cancer, including cancers of the penis, cervix, vulva, vagina, anus, and throat. Other types of HPV cause warts in different parts of the body.
HPV can be passed from one person to another during skin-to-skin contact. One way HPV is spread is through sexual activity, including vaginal and anal intercourse and even oral sex.
HPV types are given numbers. The type linked to throat cancer (including cancer of the oropharynx) is HPV16.
Most people with HPV infections of the mouth and throat have no symptoms, and only a very small percentage develop oropharyngeal cancer. Oral HPV infection is more common in men than in women. In some studies, the risk of oral HPV infection was linked to certain sexual activities, such as open mouth kissing and oral-genital contact (oral sex). Smoking also increases the risk of oral HPV infection . At this time the US Food and Drug Administration has not approved a test for HPV infection of the mouth and throat.
The number of oropharyngeal cancers linked to HPV has risen dramatically over the past few decades. HPV DNA (a sign of HPV infection) is now found in about 2 out of 3 oropharyngeal cancers and in a much smaller fraction of oral cavity cancers. The reason for the rising rate of HPV-linked cancers is unclear, although some think that it could be because of changes in sexual practices in recent decades, in particular an increase in oral sex.
Oropharyngeal cancers that contain HPV DNA tend to have a better outlook than those without HPV.
From the American Cancer Society website.