May 31, 2000 -- Gay and bisexual men are at significant risk for developing anal cancer, and testing them for the disease would save many lives, says a new study in the American Journal of Medicine.
Anal cancer in gay men is as common as cervical cancer was in women before the use of the Pap smear, the test used to screen for precancerous spots on the cervix. Both types of cancer are caused by the human papilloma virus, or HPV, which also causes genital warts. The researchers involved in this new study say that Pap smears, which have saved the lives of many women, should also be used to look for anal cancer in gay and bisexual men.
Study author Sue Goldie, MD, MPH, tells WebMD that screening for anal cancer in gay men would provide the same, if not greater, life-saving benefits as cervical cancer screening in women. Goldie is assistant professor of health policy and decision sciences, Harvard School of Public Health.
She says her study was motivated by three facts: that the number of cases of anal cancer is rising in gay men; that changes in the cells lining the anus that indicate cancer is likely to develop are easily identified with a Pap smear; and that development of this type of cancer is linked to infection with the common virus HPV. "So a study on screening seemed in order," she says.
By analyzing scientific data, Goldie and colleagues found that screening gay and bisexual men every three years would identify many cases of anal cancer early -- when they can be treated successfully -- at a cost that compares favorably with other widely used tests such as mammography for breast cancer and Pap smears for cervical cancer.
"This study clearly shows the benefit of doing anal cancer screening in gay men," Joel Palefsky, MD, the study's senior researcher, tells WebMD. "It's really very easy for clinicians to learn to do an anal Pap smear."
The reason the researchers didn't come right out and call for doctors to immediately begin offering the screening is that the health care system doesn't yet have the ability to deal with abnormal results, he says. "Physicians need to be trained to ... evaluate the lesions, and surgeons need to be trained to treat them," says Palefsky, professor of laboratory medicine and of medicine at the University of California at San Francisco.
Stephen Goldstone, MD, who was not involved in the study, tells WebMD he's been screening and treating gay men for anal cancer for several years and has found that 2.5% of these men have the disease.
"That's huge," he says. "We're trained to provide Pap screening for women but not for gay men. Contributing to the problem is the fact that gay men don't tell their physicians they're gay, and physicians don't ask. We need education on the part of the physician and the patient that this is a serious disease." Goldstone is clinical assistant professor at Mt. Sinai School of Medicine in New York.
HPV vaccines offer the best hope for keeping anal cancer rates in check in the future, Goldstone says. "Several vaccines are under development, but for now, men need to know that condoms will not protect them against HPV infection, and that genital warts are not the most serious consequence of infection," he says.