Oral HPV infection more common in men than women: Study

By Dr. Ananya Mandal, MDJan 31 2012

According to a new US study, oral human papillomavirus (HPV) infection is more common among men than women, leading to an increased risk for men of head and neck cancers. HPV causes the majority of cervical cancers, as well as genital and anal - and head and neck cancers.

The Journal of the American Medical Association (JAMA) study assessed around 5,500 people aged 14 to 69. Around 10% of men had oral HPV, compared with 3.6% of women. The researchers used data from a cross-sectional study as part of the 2009-10 National Health and Nutrition Examination Survey. They all provided a skin cell samples for testing from their mouths, and were interviewed about their lifestyles and sexual history. Overall prevalence of oral HPV infection was 7%. Prevalence of HPV increased with lifetime or recent number of partners for any kind of sex, vaginal sex, or oral sex.

Smoking and drinking are significant known risk factors for head and neck cancers. But oral HPV infection increases cancer risk by around 50%, according to the research team from Ohio State University Comprehensive Cancer Center. They add that incidence of head and neck cancers has significantly increased over the last three decades, and HPV has been directly implicated as an underlying cause.

Writing in JAMA, the team led by Dr Maura Gillison, said their findings should influence research into the existing HPV vaccines and how effective they could be in preventing oral cancers. “Vaccine efficacy against oral HPV infection is unknown, and therefore vaccination cannot currently be recommended for the primary prevention of oropharyngeal cancer. Given an analysis of US cancer registry data recently projected that the number of HPV-positive oropharyngeal cancers diagnosed each year will surpass that of invasive cervical cancers by the year 2020, perhaps such vaccine trials are warranted,” the authors write.

Jessica Harris, health information manager at Cancer Research UK, said, “As we learn how common HPV infections in the mouth are, and how they are passed on, we can understand more about who is most at risk and how people can reduce the risk of HPV-related cancers. Although there isn't yet any evidence to show whether HPV vaccination is effective at preventing oral HPV infections, results like these are vital to help inform prevention programmes in the future.”

About 12,200 women a year are diagnosed with cervical cancer, while 7,100 people a year develop HPV-related throat cancers, according to the CDC. If present trends continue, by 2020, throat cancers will overtake cervical cancers as the leading cause of HPV-related tumors, Gillison says.

“Nearly everyone who is sexually active will get a genital infection with HPV,” says Kevin Ault, an obstetrician/gynecologist at Atlanta's Emory University School of Medicine, who wasn't involved in the new study. “However, I am not sure we know that about HPV and oral infections.” Gillison says she was surprised that oral infections were so common.

In an accompanying editorial, Drexel University's Hans Schlecht says doctors should counsel patients who have oral sex to use barrier protection, such as a condom or other device. Schlecht, an infectious-disease specialist, says doctors also should look out for early signs and symptoms of throat cancer. While doctors can screen for cervical cancers, detecting and removing them in precancerous stages, doctors have no way to screen for throat cancer, which can cause unexplained weight loss, earache, difficulty speaking, difficulty swallowing or a feeling of a lump in the throat, Schlecht writes.

The Food and Drug Administration also has approved two vaccines that prevent HPV infection, designed to help protect against cervical cancer. The vaccines have been shown also to protect against vaginal, vulvar and anal cancers. Last fall, a CDC advisory panel recommended giving the vaccines to all children at age 11 or 12 — both boys and girls. Given the benefits of preventing cancer, however, Ault says the study “does argue for vaccinating everyone.” And, he says, it adds “yet another reason not to smoke.”