Cancer survivorship: What are the numbers? the epidemiology of cancer by sexual orientation and gender identity

Abstract

The lack of information on sexual orientation and gender identity in cancer registries has prevented epidemiologists from assessing cancer disparities related to these dimensions of social inequality at the individual level. Nonetheless, researchers in North America and Europe have conducted studies to estimate sexual orientation and gender identity disparities in the risk of developing or dying of certain cancers, some of which provide evidence of a higher burden of cancer among lesbian, gay, bisexual, and transgender (LGBT) populations. Specifically, U.S. investigators have found a positive association between same-sex partner household density and the incidence of breast (among women), colorectal (among women and men), and lung (among men only) cancers at the county level. At the individual level, research shows that breast cancer incidence may be slightly higher among lesbian and bisexual women relative to heterosexual women, and that the incidence of anal cancer may be higher among men who have sex with men compared to men in general. Some studies have also suggested that transgender women receiving hormone therapy may be at higher risk than the population in general of dying of lung and blood cancers. Additional research is needed to identify the long-term effect of estrogen and testosterone on the risk of developing hormone-related tumors among transgender women and men receiving hormone therapy. Further, studies that consider the influence of the lifecourse and contextual factors on outcomes along the full cancer continuum, include LGBT people of color and low-income LGBT individuals, and focus on populations in developing countries are needed.