Lesbians and bisexual women in the United States have above-average prevalence rates of several risk factors for breast and gynecologic cancers, according to a study combining data from several lesbian health surveys.1 A comparison of these data with standardized estimates for all U.S. women suggests that lesbians and bisexual women are significantly more likely to be obese, smoke cigarettes and abuse alcohol (all known cancer risk factors). Furthermore, they are significantly less likely than average to have ever used oral contraceptives and to have ever been pregnant or given birth to a live infant (all shown to be protective against ovarian and endometrial cancer). Lesbians and bisexual women are also less likely than American women overall to have health insurance and to undergo cancer screenings. The breast cancer rate for lesbians in this study is not significantly different from that for American women overall.
To assess whether lesbians and bisexual women are at increased risk of certain cancers, researchers analyzed questionnaire responses from seven lesbian health surveys conducted in the United States between 1987 and 1996. Data from the surveys were pooled, and health and demographic variables were coded into a common format so they could be compared. Prevalence rates of health-related behaviors and self-reported breast cancer history were calculated from the pooled data and analyzed against data from two large, national samples of U.S. women, standardized to match the age, race and ethnicity, educational level and geographic location of the lesbian health survey data.
In all, 11,876 women were involved in the study. Eighty-seven percent of the women surveyed were self-defined lesbians, while 12% considered themselves bisexual. (The researchers used the term "lesbian" to collectively refer to both groups.) Some 86% were white and non-Hispanic. On the whole, the women surveyed were highly educated: Forty-two percent had attended graduate school and 26% had a college degree, while 32% had a high school education or less. Twenty-eight percent of the women surveyed were aged 18-29, 63% were 30-49 and 8% were 50-75. The study population was almost evenly distributed among the Northeastern, Midwestern, Southern and Western regions of the United States. Even though the study sample was large and drawn from diverse geographic locations, the researchers noted that the study was not population-based and may not truly represent the total U.S. population of lesbians.
The researchers found that lesbians were more likely than women overall to have various behavioral risk factors for breast and gynecologic cancer. Nearly three in 10 lesbians surveyed were obese, compared with about one in five women overall; nevertheless, lesbians were less likely than average to consider themselves overweight (44% vs. 56%). Although there was no significant difference in current alcohol use between lesbians and women overall, the same was not true for problem drinking. More than 12% of lesbians reported having a history of problems with alcohol, a rate far higher than the 4% standardized estimate of women nationally who reported having five or more drinks almost every day. Lesbians were also more likely than average to currently use tobacco (21% vs. 16%) or to have used tobacco in the past (34% vs. 20%).
Sixty percent of lesbians surveyed reported having a history of heterosexual relations, yet they were significantly less likely than women from the national surveys ever to have used birth control pills (36% vs. 80%). Lesbians were also less likely than average ever to have been pregnant (28% vs. 67%) or to have given birth to a live infant (16% vs. 57%).
Furthermore, a smaller proportion of lesbians than of women overall were covered by health insurance (86% vs. 93%). Lesbians also were less likely to undergo cancer screenings: Only 73% reported having a recent pelvic examination, in comparison with the standardized estimate of 87% for women nationally, and lesbians in their 40s were less likely than women overall ever to have had a mammogram (73% vs. 87%).
Contrary to their expectations, the researchers did not find a significant difference in the incidence of breast cancer between lesbians and women nationally (1% of each). They speculated that a young mean age among respondents (36 years), healthy-volunteer bias and residual confounding all could have caused underestimation of the prevalence of cancer among lesbians.
The researchers point out that although an increased incidence of breast cancer in lesbians was not found, lesbians may still have an increased risk of various other negative health effects of smoking, obesity and alcohol, in addition to cancer. The researchers comment that "despite the extensive public health efforts in the United States promoting weight loss, smoking cessation, reduced alcohol consumption, and use of preventive screening, lesbians and bisexual women, an apparently logical target group given our findings here, have not been a particular focus of public health interventions."
The researchers also stress that many health care providers may not be treating lesbians properly because of a lack of knowledge and understanding. They add, "If public health is truly for everyone, the results of the current study call for developing culturally competent interventions targeted to the differential risk patterns evidenced by lesbians and bisexual women." --J. Rosenberg
1. Cochran SD et al., Cancer-related risk indicators and preventive screening behaviors among lesbians and bisexual women, American Journal of Public Health, 2001, 91(4):591-597.