Studies and reports whether being lesbian or bisexual is associated with a higher risk of breast cancer have been patchy and often with contradictory findings. National cancer registries, surveys and databanks do not routinely gather information on people's sexual orientation.

While advocates for ethnic, racial and geographical groups have managed to gather data and argue their case compellingly regarding disparities in health status and access to proper health care, those in the lesbian community cannot - simply, because there is no easy way to gather such information.

Liz Margolies writes in the The National LGBT Cancer Network and explains that while some research focusing on lesbian cancer risks and experiences has been carried out, the findings have been "inconsistent" because of the small sample sizes.

Liz Margolies urges organizations, such as the Lesbian Health Research Center at the UC Medical Center in San Francisco, and others like it, to carry out further large-scale studies on lesbians and cancer. With proper funding, some really relevant studies with accurate results could be achieved.

The National LGBT Cancer Network says that a "cluster of risk factors" theory still dominates among some people regarding lesbians and breast cancer risk. This theory will most likely prevail until some accurate large-scale studies are performed.

Lesbian and heterosexual women are not different physiologically or genetically. Therefore, any variations in breast cancer rates most likely result from the stress and stigma of living in a society where homophobia and discrimination continue to impact. The resulting behaviours probably have an effect on cancer risk, which could perhaps even double a lesbian's chances of developing cancer when taken together. It is important to point out that without proper research, these factors are only theoretical.

Margolies emphasizes that nobody is sure what impact each possible behaviour factor might have. A considerable number of people with established risk factors never have cancer.

The four most commonly quoted risk factors used in recent research that focused on lesbians and cancer risk include:
  • Smoking - according to some studies, regular tobacco smoking is more prevalent among lesbian adults than heterosexual women
  • Alcohol consumption - alcohol abuse, and/or heavy regular drinking appears to be more common among lesbians, compared to other women, according to some research
  • Bodyweight - lesbians are said to be more likely, on average, to weigh more than other women of the same age and height
  • Pregnancy and breastfeeding - it is likely that a higher percentage of heterosexual women will breastfeed during their lives, compared to lesbian women. Breastfeeding has been shown to reduce breast cancer risk. Liz Margolies mentions that lesbians are less likely to become pregnant and have children before they are 30 years old (apparently, getting pregnant to full term before 30 years of age reduces cancer risk).
  • Cancer screening - studies have consistently shown that a lower percentage of lesbians receive mammographies, pap smears and colonoscopies compared to other women. Liz Margolies believes this is due in part to financial problems, and a belief by the lesbian that she will not be welcomed - either because of a perceived fear or due to previous experience.
Even if a lesbian is in a stable relationship, she is less likely to have health insurance coverage from her partner because she will not be seen as a spouse. With heterosexual women, there is a greater chance, if her partner receives coverage through his employer, that she will be covered as well.

A significant number of lesbians do not seek medical help for routine screenings because of a fear of being shunned or ill-treated by health staff. As mentioned above, this is sometimes the result of real experiences, Liz Margolies writes.

Even if routine screenings are provided free of charge, until health care providers understand what is relevant to a lesbian's life and needs, for example, providing forms that are relevant, it is unlikely that much will change - screening rates among lesbians will continue to be lower compared to heterosexual women.

The tragic consequence of these barriers to routine screening is that a higher percentage of lesbians are diagnosed with cancer at later stages of the disease - when it is much harder to treat.

Liz Margolies, who lives in New York, imagines what it must be like for a lesbian who lives in a small town, is diagnosed with cancer, and seeks out support groups, only to find that all of them are aimed at heterosexual women.

Written by Christian Nordqvist (adapted from a text written by Liz Margolies )