September 14, 2007

HPV’s link to head and neck cancer investigated

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Dell Yarbrough, M.D.

HPV’s link to head and neck cancer investigated

The human papillomavirus (HPV) has been implicated as a cause of cervical cancer in women, but there's another devastating form of cancer also linked to HPV infection — head and neck cancer — and almost no one is talking about it.

“Right now I think the public and most physicians have no idea that HPV relates to head and neck cancer,” said Dell Yarbrough, M.D., Vanderbilt-Ingram Cancer Center surgical oncologist. “In cancers of the oropharynx, which includes the tonsils, the base of the tongue, and part of the throat, about half of those tumors are HPV-positive. In the oral cavity, between 10 and 15 percent of tumors test positive for HPV, although here at Vanderbilt-Ingram we're seeing up to 20 percent.”

HPV is one of the most common sexually transmitted diseases in the world. The Centers for Disease Control and Prevention (CDC) estimates nearly 6.2 million new genital HPV cases occur in the United States each year. Now researchers have documented a rise in some types of head and neck cancer related to HPV, especially cancer in the tonsils. The spike in tonsillar cancer coincides with reported changes in sexual habits among young people, including earlier age of sexual activity and an increase in oral sex.

“Head and neck cancer used to be a disease of people in their 50s and 60s who smoked and drank heavily,” said Yarbrough. “The younger population was at very low risk until recently. But now we're seeing an increased incidence in young nonsmokers and nondrinkers. Everybody assumes oral sex is a possible link to HPV infection, but if your partner had oral sex and is a carrier of the virus, that could be another link. No one is sure.”

Cancer of the head and neck is often aggressive. Symptoms include a hoarse voice, pain in the nose, mouth or throat, a lump or bump in the neck, ulcers in the mouth, loose teeth or a change in swallowing or speech.

The head and neck cancer team at Vanderbilt-Ingram is testing all patients with oropharyngeal or oral cancers to find out if their tumors are HPV-positive.

Physicians have discovered those patients do better with treatment and have better survival than patients whose tumors are HPV-negative.

“Head and neck cancer is devastating,” Yarbrough said. “The overall cure rate of all but the earliest stages of head and neck squamous cell carcinoma is hovering around 60 percent and the percentage hasn't changed in decades. So that means if 10 patients come in to see us, only six are going to survive.”

There are more than 100 subtypes of HPV. Types 16 and 18 usually are implicated in cervical cancer.

Those are the same subtypes often found in HPV-positive head and neck cancers. Gardasil — a new vaccine approved last year — is effective against those HPV subtypes but the vaccine is only approved for use in girls and women ages 9 to 26.

The discovery of a link between the virus and head and neck cancer raises the possibility of vaccinating young men.

“I think it's reasonable to think about vaccinating both young men and women because of the risk of head and neck cancer,” Yarbrough said.