Sexual and gender minority populations and skin cancer: new data and renewed priorities

Sexual and gender minority (SGM) persons include, but are not limited to, individuals who identify as lesbian, gay, bisexual, or transgender, as well as individuals whose sexual orientation, gender identity or expression, or reproductive development are characterized by non-binary constructs of sexual orientation, gender, and/or sex.¹ The National Cancer Institute has called for specific research to “assess cancer risk to inform improved decision-making, risk reduction interventions, and screening options for early cancer detection in SGM populations.”¹ Notably, population-based data on skin cancer epidemiology in SGM persons remain inadequate. Without robust epidemiologic data, it has been challenging for dermatologists to recognize and articulate their specific roles within broader national conversations on improving SGM health. Emerging skin cancer data, particularly among gay and bisexual men, indicate unmet needs for skin cancer prevention in specific SGM subpopulations.²

In this issue of JAMA Dermatology, Singer and colleagues expanded the literature on skin cancer burden in SGM populations using U.S. population-based survey data.^3,4 In two similarly designed cross-sectional studies using the Behavioral Risk Factor Surveillance System (BRFSS) surveys, self-reported lifetime history of any skin cancer was assessed across sexual orientation and gender identity (SOGI) groups in pooled data from 37 states across 2014–2018. Consistent with previously reported differences in skin cancer history and risk factors related to sexual orientation,⁵ gay and bisexual men reported 26%−48% higher odds of being diagnosed with skin cancer compared to matched heterosexual men, while bisexual women reported 22% lower odds of being diagnosed with skin cancer compared to matched heterosexual women.³ New to the literature, gender nonconforming persons reported double the adjusted odds of being diagnosed with skin cancer as compared to cisgender men, while no difference was seen in transgender men and transgender women as compared to cisgender men.⁴ While the differences in prevalence estimates are small in absolute magnitude, these data provide additional concrete examples of disproportionate skin cancer burden within SGM subpopulations.

Epidemiologic studies of skin cancer in SGM populations are difficult to perform and the data examined the by Singer and colleagues should not be taken for granted. Key demographic variables relevant to SGM persons have historically not been collected. The Centers for Disease Control and Prevention (CDC) has allegedly threatened to remove the optional SOGI data collection module from the BRFSS starting in 2019, which would eliminate an important data source aimed to understand the health status of SGM populations.⁶ While the CDC has since denied this plan,⁷ persistent skin cancer differences in SGM subpopulations highlight the important roles that dermatologists, along with the rest of organized medicine, have in advocating for the continued collection of SOGI and dermatology-related disease data in federal health surveys.

Without standardized and self-reported SOGI data such as those collected in the BRFSS surveys, prior studies were unable to examine the health of gender non-conforming persons, who may face disproportionate health risks. Using limited data related to gender minority status, prior studies have examined melanoma cases in gender minority patients in state-based cancer registries.^8,9 Cancer registries collected data on “sex”, with categories including male and female as well as the outdated categories of “other (hermaphrodite)” and “transsexual.” The proportion of melanoma diagnosed among all reported cancers in transgender patients, as determined by the “transsexual” category, was lower than the corresponding proportions in cisgender men and cisgender women, with proportional incidence ratios of 0.25 (95% confidence interval [CI], 0.11–0.49) and 0.34 (95% CI, 0.15–0.67) in the National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) and 0.5 (95% CI, 0.4–0.8) and 0.7 (95% CI, 0.5–1.0) in the North American Association of Central Cancer Registries, respectively. However, these data could not estimate melanoma cumulative incidence because they lacked information on the number of transgender persons at risk of developing melanomas as denominators.^8,9 Data on keratinocyte carcinomas, which are not reportable to cancer registries, were not available.

Melanoma incidence was additionally examined in cohort studies of transgender persons, which validated transgender status using a combination of diagnostic codes, pharmacy data, surgical procedural codes, and manual chart review. In the Study of Transition, Outcomes and Gender, which examined a validated cohort of transgender persons enrolled in three Kaiser Permanente sites, the incidence rate of melanoma in transgender adults did not differ from that of cisgender men or cisgender women, with adjusted hazard ratios of 0.9 (95% CI, 0.4–2.0) and 1.0 (95% CI, 0.4–2.3), respectively.¹⁰ On the other hand, in the Veterans Affairs electronic medical records, transfeminine veterans had higher risks of melanoma compared to cisgender male and cisgender female veterans (adjusted hazards ratios 1.7 (95% CI 1.0–2.9) and 2.7 (95% CI 1.5–4.7), respectively).¹¹ Future research should consider intersectionality between SGM identity and additional sociodemographic factors (such as age, race/ethnicity, veterans status) and should perform stratified analyses to identify subpopulations that face disproportionate skin cancer risks.

Strengths and limitations of the two BRFSS-based studies should also be considered. Population-based data are less prone to surveillance bias related to healthcare utilization, especially since SGM persons may face higher barriers to access healthcare services. However, the data were limited to states that collect SOGI data in the BRFSS optional module; health outcomes of SGM persons in states that did not administer the optional SOGI module may differ. Self-reported history of skin cancer may be prone to biases related to self-report and survivorship. For example, gay and bisexual men report higher rates of skin examination as compared with heterosexual men, which could contribute to higher self-reported rates of skin cancer diagnosis.⁵ Moreover, the risk of aggressive melanoma by SGM status may not be compared using these data, since survey completion necessitates the respondent to survive cancer. BRFSS did not collect data on skin cancer subtypes and locations to generate hypotheses on the relative contributions of risk factors such as human papillomavirus (HPV) infections or ultraviolet radiation exposure. High prevalence of HPV infections in gay and bisexual men may contribute to anal, oral, or genital squamous cell carcinomas.⁵ Some BRFSS surveys contain optional modules with data on indoor tanning use and excessive sun exposure, which may enable future studies of potential mediators of skin cancer differences by SOGI status. Lastly, the authors designated cisgender men as the sole reference category from which to compare the skin cancer risks of all gender minority patients. Future studies should compare health outcomes of gender minority patients to both cisgender men and cisgender women to create a fuller understanding of biological, behavioral, and sociocultural factors that influence skin cancer epidemiology. While prevalence is useful in providing a snapshot of skin cancer burden, incidence data is required to understand the risks of skin cancer development. Further investigation on the associations between sexual orientation, gender identity, and skin cancer will require rigorously designed and sufficiently powered longitudinal data that collect SOGI data and skin cancer risk factors.

Now that differences have been identified, the next step is to understand why these differences exist and how they can be mitigated. A recent qualitative study identified salient factors for indoor tanning among gay and bisexual men to inform targeted skin cancer prevention approaches, such as appearance-focused interventions, community-oriented messaging, and policy efforts to reduce tanning access.¹² An ecological study showed greater concentrations of indoor tanning salons in neighborhoods with higher proportions of same-sex male partner households.¹³ Many important research and clinical questions remain: What are the relevant and modifiable risk factors that mediate higher skin cancer risks in gender non-conforming persons? How should skin cancer prevention be incorporated into overall health promotion among SGM persons? How can public health interventions on skin cancer prevention be expanded to target SGM subpopulations facing disproportionate skin cancer risks? How should dermatologists incorporate data on skin cancer epidemiology to improve the clinical care of SGM patients?

Despite stated national priorities, skin diseases have remained largely hidden from existing research on SGM health. Fortunately, that may be changing. In March 2019, the National Institutes of Health – including the National Cancer Institute and the National Institute of Arthritis and Musculoskeletal and Skin Diseases – issued a Notice of Special Interest in Research on the Health of SGM Populations.¹ That same month, the American Academy of Dermatology approved a Position Statement on Sexual and Gender Minority Health in Dermatology that supports SGM-inclusive research, education, and clinical care.¹⁴ To better understand SGM health, researchers cannot rely only on SOGI and dermatology-related health data collected in optional BRFSS modules, particularly if federal SOGI data collection remains in jeopardy. Understanding dermatology-related diseases in SGM populations will require dermatologists to 1) collect SOGI data in routine clinical practice and research, as many have advocated,^14,15 2) investigate potential differences in dermatology-related health outcomes beyond skin cancer, and 3) collaborate across disciplines to advocate for the inclusion of dermatology-related outcomes in ongoing and future SGM health studies. It is time for dermatologists to lend their expertise to help prioritize the dermatology-related health of sexual and gender minority persons.