A B S T R A C TObjectives. This study examined whether lesbians are at increased risk for certain cancers as a result of an accumulation of behavioral risk factors and difficulties in accessing health care.Methods. Prevalence estimates of behavioral risk factors (nulliparity, obesity, smoking, and alcohol use), cancer screening behaviors, and self-reported breast cancer histories derived from 7 independently conducted surveys of lesbians/bisexual women (n = 11 876) were compared with national estimates for women.Results. In comparison with adjusted estimates for the US female population, lesbians/bisexual women exhibited greater prevalence rates of obesity, alcohol use, and tobacco use and lower rates of parity and birth control pill use. These women were also less likely to have health insurance coverage or to have had a recent pelvic examination or mammogram. Self-reported histories of breast cancer, however, did not differ from adjusted US female population estimates.Conclusions. Lesbians and bisexual women differ from heterosexual women in patterns of health risk. These women would be expected to be at especially greater risk for chronic diseases linked to smoking and obesity. Whether or not lesbians are at higher risk than other women for breast and gynecologic cancer is an emerging controversy.1-8 A recent Institute of Medicine report 9 documented the potential for double to triple the risk of breast cancer, in particular, among lesbians in comparison with other women. Possible reasons are greater prevalence rates of known reproductive-related risk factors, including nulliparity or older age at first childbirth, 10-12 and behavioral risk factors, including more frequent alcohol consumption [13][14][15][16] and perhaps obesity.11,17 Although none of these individual risk factors is exclusive to lesbians, the possible concentration of these risks within a single group is unique.Coupled with worries about patterns of higher risk are concerns that lesbians may be less likely than heterosexual women to use preventive cancer-related screening services such as mammography or Papanicolaou (Pap) tests. 1,11,18,19 Lower rates of screening, if they exist, might result in later detection of cancers, thereby increasing morbidity and mortality rates. 20 Several factors have been hypothesized as barriers to the use of routine screening in this population, including experiences with discrimination in health care settings, lower rates of insurance in the absence of the safety net of spousal health benefits, and fewer cues, such as contraceptive needs, to trigger seeking of routine gynecologic care. 1,9,19,[21][22][23] Nevertheless, little is known empirically about behavioral risks in this population.9 Most existing surveys of lesbian health and health care behaviors have relied on relatively small convenience samples drawn from local community settings without heterosexual controls. Methodological barriers to population-based sampling are daunting, given that lesbians represent both a hidden and a small subpopulation, est...