SEATTLE -- Michael Douglas' announcement that his throat cancer was caused by the sexually-transmitted human papillomavirus (HPV) surprised many who believed the infection only caused cervical cancer in women. But in fact, HPV-related cancers affecting both men and women are on the rise in the United States and very few men are getting the vaccine that could protect them.
HPV is the most common sexually transmitted infection in the United States, according to the U.S. Centers for Disease Control and Prevention. Nearly all sexually-active men and women are infected at some point in their lives.
The majority of people have no symptoms or serious health impacts from HPV, but in some cases the infection lingers over time and can cause cancer.
Cervical cancer is the most common HPV-related cancer, but the virus can also cause anal, penile and oropharyngeal (back of the throat, base of the tongue and tonsils) cancers in both men and women. Of the 22,000 HPV-associated cancers reported each year in the United States, the American Cancer Society reports 7,000 occur in men.
And while cervical cancer rates are dropping do to successful screening, oropharyngeal and anal cancers are on the rise. In fact, oropharyngeal cancer is expected to become more common than cervical cancer by 2020.
There are no screening practices for anal, penile and oropharyngeal cancers and no HPV test recommended for men. The only preventative measure is the HPV vaccine Gardasil, recommended to boys and young men through age 21. Still, only 8.9 percent of boys ages 13 to 17 were vaccinated for HPV in Washington in 2011.
"The uptake of vaccine in this country is very disappointing, especially among boys," said Dr. Denise Galloway, interim director of the Human Biology Division at Fred Hutchinson Cancer Research Center. "If you could prevent a certain type of cancer why wouldn't you?"
Galloway said much of the public does not know that men should be vaccinated because HPV vaccines were first approved in 2006 for women only. It wasn't until 2009 that U.S. Food and Drug Administration today approved use of Gardasil in men for the prevention of genital warts. In 2011, the CDC recommended that boys be vaccinated with girls at ages 11 to 12.
"It takes a long time for information to get out to general practitioners," Galloway said.
Rachel Katzenellenbogen, assistant professor of Pediatrics at Seattle Children's Hospital, said physician recommendations are the most important factor in convincing a parent to vaccinate their child. But, she said family physicians are sometimes poorly educated on HPV-related cancers because they do not treat cancer patients.
The vaccine is most effective if given before the patient becomes sexually active, but some parents are concerned it may encourage their child to have sex, Galloway said.
Another common misunderstanding is that boys only need to be vaccinated to protect girls from cancer.
"I think it's hard for a parent to vaccinate on behalf of someone else," Katzenellenbogen said.
The vaccine can also be expensive, costing $130 for each of the three doses, according to the CDC.
Studies have shown that vaccinating men becomes less cost-effective if the majority of women have received the HPV-vaccine, but Galloway say's we're not there yet. Washington has one of the highest vaccination rates in the country with 40 percent of girls receiving all three doses. Still, that's far below the U.S. Healthy People 2020 target of 80 percent.
Even if every woman in the United States was vaccinated for HPV Dr. Vy Chu of Capitol Hill Medical said men having sex with men would still be at risk. The CDC reports these men are about 17 times more likely to develop anal cancer than men who only have sex with women, and men with HIV are 30 times more likely.
The CDC recommends men who have sex with men and HIV-positive men be vaccinated for HPV through age 26.
Regardless of their sexuality, Chu urges all young men to get the vaccine.
"We have to move beyond just cervical cancer," he said. "These are diseases and cancers that are 100-percent preventable if you just get the vaccine."