February 2, 2012 | by City of Hope Staff
The human papillomavirus, or HPV, has gotten a lot of attention because of its association with cervical cancer — but it also can infect the throat and mouth and cause oral cancers. Recent research suggests it causes more of these oral cancers than experts previously thought.
A study in the Journal of the American Medical Association showed that about 7 percent of men and women between ages 14 and 69 had HPV in the mouth, and oral infection is nearly three times as common in men as in women. (About one in every 10 men in the study had it).
Over the past decade, cases of mouth and throat cancers related to HPV have grown by more than 4 percent ever year, and the majority are in the throat (base of tongue and tonsils) — something that might be linked to changes in sexual practices like oral sex, according to the American Cancer Society. Whatever the cause, specialists like City of Hope’s Joel Epstein, D.M.D., M.S.D., director of the Division of Oral Medicine, are seeing the result in their clinics.
HPV-related cancers of the mouth and throat — primarily the oropharynx — are on the rise while the overall incidence rate of cancers is declining. Smoking is the other major factor that contributes to mouth and orophayrnx cancers, but those HPV-unrelated cases have been on a steady decline.
Over 90 percent of HPV-related oropharyx cancers are due to the HPV 16 strain of the virus, which is also a major virus strain in cervical cancers. The two HPV vaccines currently approved for girls and young women inoculate against HPV 16, among other strains.
Last October, an advisory committee for the Centers for Disease Control and Prevention recommended HPV vaccination for young boys, similar to the recommendations they had provided for young girls earlier. [The American Academy of Pediatrics issued a similar recommendation this week.>
From an epidemiological perspective, it makes sense to vaccinate the population during their childhood, but there are cost issues that need to be considered as well. We don’t know if HPV infection is an epidemic in the starting stages or if HPV-related cancers will remain relatively rare in comparison to other cancers.
HPV-related oropharynx cancers started rising in 1985, he notes, and HPV has a long incubation period before leading to cervical, anal or head and neck cancers. Only a portion of infected people who do not clear the virus may be at risk for cancers. That sounds very similar, he says, to another sexually transmitted virus that the general public is familiar with: human immunodeficiency virus, or HIV.
About 40,250 Americans will be diagnosed this year with some form of cancer in the mouth or throat, according to the American Cancer Society. The death rate is continuing to drop, with about 7,850 deaths attributed to the disease.