• 5/22/2008
  • Chicago, IL
  • Brian Boyer
  • Medill Reports (news.medill.northwestern.edu)

Men are neither vaccinated nor screened for human papillomavirus, but two university studies suggested last week that it may be the cause of cancer for many men, and that those cancers could have been prevented.

The virus, better known as HPV, is the primary cause of cervical cancer in women. Recent research, at the University of Michigan and University of Louisville, suggests that it is also the cause of a disease that disproportionately affects men, cancers of the head and neck.

“You should be testing everybody,” said Payal Desai, leader of a pilot study at the Louisville’s James Graham Brown Cancer Center. Both men and women carry HPV, the virus that will affect at least 50 percent of sexually active people, according to the Food and Drug Administration, though only a fraction of those will develop cancer.

More than 35,000 new cases of head and neck cancer are expected to be diagnosed in the United States in 2008, according to the American Cancer Society. Twice as many men as women will develop the disease, which the society estimates will kill 7,590 Americans this year.

Currently a screening test only exists for women. Similarly, a vaccine for HPV exists, but is only approved for use in women ages 9 to 26. Studies are under way to test the efficacy of the HPV vaccine in men, according to the FDA.

If the vaccine were successful in preventing HPV infections in men, the studies suggest it is possible that a significant number of cancer cases in men could be avoided.

In one study, tissue samples from 43 head and neck cancer patients were tested by the Louisville team. They found that almost one-third of the samples tested positive for HPV, specifically the strain of the virus known as HPV 16.

In the other study, at Michigan’s Comprehensive Cancer Center, had similar findings. More than one-third of the 66 head and neck cancer cases they examined tested positive for HPV 16. This study’s primary finding was encouraging: The HPV-associated tumors responded significantly better to treatment than those not associated with HPV.

In women, HPV types 16 and 18 are responsible for 70 percent of cervical cancer cases. The American Cancer Society estimates that 11,070 cases will be diagnosed, and that the disease will kill 3,870 women in the United States in 2008.

Infection by strains 16 and 18 can be prevented through vaccination, with almost 100 percent effectiveness. The drug Gardasil, first made available to young women in 2006, also vaccinates against types 6 and 11, which are responsible for 90 percent genital warts cases.

Note:
1. Desai presented the findings of their study May 15 at the American College of Physicians Internal Medicine Conference. The results have not yet been published. The University of Michigan study was published online May 12 in the Journal of Clinical Oncology. In February, another study, at the National Cancer Institute and Johns Hopkins Medical Insitutions, suggested a link in men between HPV and oral cancer.