Print this page

New Vaccine for Cervical Cancer Could Prove Useful in Men, Too

By DAVID TULLER

New York Times

January 30, 2007

The new vaccine against human papillomavirus, which became available last summer, could potentially prevent thousands of cases of cervical cancer. But doctors hope the vaccine will be able to prevent a less well-known, but potentially fatal, disease in gay men, anal cancer. The same strains of HPV cause both cancers.

Although anal cancer can affect anyone, it is most common among men with histories of receptive anal intercourse — an annual rate of about 35 cases per 100,000, and perhaps twice that for those infected with H.I.V., which weakens the immune system.

The Food and Drug Administration approved the HPV vaccine last year for girls and women from 9 to 26 after studies indicated that it was extremely effective against infection by four of the dozens of strains of HPV, including the ones responsible for most cases of cervical and anal cancer, as well as genital and anal warts.

“The cervix is similar biologically to the anus, so there’s plenty of hope that it will work there also,” said Dr. Joel Palefsky, a professor of medicine at the University of California, San Francisco.

But he cautioned that its effectiveness against anal cancer remained to be proved.

The anal cancer rate for gay men is similar to cervical cancer rates before the advent of Pap smears, the test that can detect precancerous cell abnormalities. In recent years, some doctors who treat gay men have advised their patients to undergo anal Pap smears as part of routine preventive care.

HPV is the most common sexually transmitted infection in the United States, with 6.2 million people infected each year, according to the Centers for Disease Control and Prevention, though many people clear the virus without having symptoms or knowing that they were infected.

Many gay men do not realize they have an elevated risk of anal cancer.

David Maxim, an artist in San Francisco, said he had vaguely heard of HPV when he learned that he had anal cancer several years ago. “I had no idea about it because no one ever talked about it, although these days more gay men seem to be aware of it,” said Mr. Maxim, who was successfully treated with radiation and chemotherapy.

Regulators in Australia and the European Union have approved the vaccine, called Gardasil and made by Merck, for boys ages 9 to 15. They cited data showing that it produced an immune response in boys, though its effectiveness in preventing infection in sexually active men has not been proved.

As with prescription drugs, doctors in the United States can provide the vaccine “off label” to anyone. “The approval is for marketing and distribution, but medical providers can use it in ways they feel is appropriate,” said Dr. Jeffrey Klausner, director of S.T.D. prevention at the San Francisco Department of Public Health.

Dr. Eliav Barr, a director of clinical research at Merck, said he had heard that some men were receiving the vaccine, but added that the company was barred from promoting it for men unless the F.D.A. approved it for that use.

That is unlikely to occur for at least a couple of years. Merck is sponsoring a clinical trial of Gardasil in 4,000 men, including 500 self-identified gay men. The first results are expected toward the end of next year.

Recruiting gay men has been challenging, researchers said. The vaccine is intended to prevent an initial infection with the virus, but many people become infected soon after becoming sexually active. For the gay arm of the study, Merck has recruited men from 16 to 26 who have had no more than five sexual partners. The difficulty is that many gay men come to accept their sexual orientation only after an experimentation period.

“These have to be men who have sex with men but who have not had too much sex with men,” said James Maynard, a program officer at the Fenway Institute, a research organization in Boston that focuses on gay and lesbian health and is a site of the HPV trial. “The more sex you’ve had, the greater the probability you’ve been infected with HPV.”

Article link: http://www.nytimes.com/2007/01/30/health/30virus.html