A new study conducted in Denmark has found that, with few exceptions, cancer rates among gays and lesbians in marriage-like relationships are the same as those in the general population.

Whether these results hold true for single people in the gay and lesbian community, or for homosexuals in other countries, is not known, however. The finding intrigues health advocates for lesbian and gay communities in the United States, who say more research is needed to determine how cancer risk differs among homosexual and heterosexual populations – and how to eliminate any disparities that may exist.

"Different communities… have different risk factors, they have different needs and characteristics, and research needs to address those," said Kathleen DeBold, executive director of The Mautner Project, a non-profit group that provides services, education and advocacy to lesbians with cancer. (The organization also provides contact information for other feminist and lesbian cancer projects across the country.)

One cancer, Kaposi's sarcoma, is known to be more common among gay men infected with HIV, the virus that causes AIDS. However, the risks of other cancers in gay and lesbian populations are largely unknown. Very few studies have been conducted specifically on cancer rates in these groups.

There are some reasons to believe that lesbians (at least in the United States) might be at higher risk for breast and gynecologic cancers. The Women's Health Initiative and other research suggests more breast cancer risk factors among lesbians. They're less likely to have children or to use birth control pills, are more likely to use alcohol, and are more likely to be overweight than heterosexual women. Lesbians are also less likely to get gynecologic exams on a regular basis, meaning that problems like precancerous lesions of the cervix might not be detected. But these ideas have yet to be well studied.

Morten Frisch, MD, PhD, from the Danish Epidemiology Science Center in Copenhagen, Denmark, and colleagues followed more than 5,000 Danish men and women in registered same-sex partnerships for an average of more than four years. They compared the rates of cancer seen in these people with the rates expected to be seen in the general population. The researchers published their results in the American Journal of Epidemiology (Vol. 157, No. 11: 966-972).

Overall, the men in the study were about twice as likely to develop cancer as would be expected in the general population. But almost all of this excess risk was due to three types of cancer. Kaposi’s sarcoma, known to be linked to HIV/AIDS, was more than 100 times more common in gay men, and non-Hodgkin’s lymphoma, also often related to HIV/AIDS, was 15 times more common. (About 10% of the men in the study had been diagnosed with AIDS.) Anal cancer, which is thought to be linked to sexually-transmitted human papillomavirus (HPV) infection, was 31 times more common in gay men.

When these three cancers were removed from the analysis, however, gay men’s overall cancer risk was the same as that of the general population.

Among lesbians, none of the cancers studied were significantly more common than those expected in the general population, including breast cancer and cervical cancer. However, there were fewer cases of precancerous cervical lesions than would have been expected. The study authors suggested that this might reflect low screening rates among homosexual women. Many women may be uncomfortable with gynecologic exams, or may feel they are not needed because they are not at risk for HPV infection, the primary cause of cervical cancer. The authors pointed out that this belief is not true, however, because HPV infections are "not uncommon," even among homosexual women who have never had sex with men.

The researchers were quick to acknowledge that their study has some drawbacks, however. The average age of those in the study was 38, which is younger than when many cancers become most common. The study also only looked at those people who were in registered partnerships, which was likely only “one to a few percent” of the total gay and lesbian population in the country. The findings, therefore, may not apply to homosexual men and women not in monogamous relationships.

The findings also may not hold true for homosexual couples in the United States, because of the differences in health care access and how homosexuality is viewed in American society, said The Mautner Project's DeBold.

Denmark has universal health care, in sharp contrast to the United States, where millions of people have no health insurance. This problem is particularly acute among homosexuals, DeBold said.

"Unlike heterosexual couples, we can't get on our partner's health care because we can't get married," she said. Even when homosexual partners can be insured, the costs are often prohibitive, she added.

Another major problem is discrimination against homosexuals, both in the health care system and society at large, DeBold said. "Denmark is light years ahead of the United States in recognizing the humanity of LGBT (lesbian, gay, bisexual and transgender) people."

Denmark was the first European country to legally recognize same-sex partnerships, passing a law in 1989. In the United States, however, DeBold said, anti-sodomy laws and societal disapproval have made many homosexuals fearful of revealing their sexual orientation to their doctors. "When you have that climate of fear, people don't go to the doctor to get preventive care," DeBold said.

So how can these disparities be addressed? Education – of health care workers, insurers and people in the gay and lesbian community itself – is one step. The Mautner Project holds training sessions called "Removing the Barriers" designed to teach health care providers more effective ways of dealing with their lesbian patients. The Gay and Lesbian Medical Association also engages in advocacy to eliminate health care disparities due to sexual orientation.

Community outreach programs need to be designed to specifically target the gay community, said Ronit Elk, PhD, scientific program director for cancer control and prevention research at the American Cancer Society.

"We can’t expect people to get preventive care just because we say it’s beneficial. What we have to do is find ways to reach the gay community and discover a common language so that we can work together effectively. Training health care professionals to become sensitive to the needs of this community is also essential. Only in this way can we ensure that we provide care that’s accessible and accepting of all."

American Cancer Society staff and volunteers are working with underserved communities to understand and reduce the barriers that prevent people from having timely cancer screening tests or from getting appropriate cancer treatment. For information or to volunteer call 1-800-ACS-2345.

The American Cancer Society Cancer Survivors Network® (CSN) offers recorded discussions and interviews with lesbian survivors and their partners as well as a discussion board for lesbian survivors, partners and caregivers. Discussions and interviews with gay men affected by cancer are in production and will be available on the CSN site by September.