It’s difficult to find consistent data about cancer rates within the bisexual population in the U.S. National cancer registries such as SEER do not yet include data on sexual orientation or gender identity, leaving bisexual people buried within the data. According to a review of numerous studies, databases that address sexual orientation and gender identity tend to lump gay men, lesbians, and bisexuals into one LGB group, or they focus on specific geographic or demographic groups that may not be nationally representative. (Quinn, 2015)
Researchers have tried to work around this dilemma by examining associations between cancer incidence and the concentration of sexual minorities in a geographic area. One study in California used county-level survey data that includes bisexuality as a category among sexual orientations and compared it with cancer incidence data in those counties from the California Cancer Registry. It found that areas with a higher concentration of bisexual men had a higher incidence of colorectal cancer, and thatareas with a higher concentration of bisexual women had a higher incidence of lung and colorectal cancer. (Boehmer, 2014) And yet, the study admits that this research method cannot link sexual minority status to cancer risk in individuals, nor can it generalize from counties in California to the bisexual population nationally.
Another study that cross-referenced data from California health surveys with the National Health Interview Survey found that men who identified themselves as gay or bisexual reported more frequent indoor tanning and higher rates of skin cancer than heterosexual men. (Mansh, 2015) Since indoor tanning is known to cause skin cancer, this correlation is no surprise.
Why might there be increased cancer rates in bisexual men and women? Several studies have found that bisexual women and men are at high risk for heavy smoking, heavy drinking, and high levels of sexually transmitted infections (Everett, 2014), including the cancer-causing human papilloma virus (HPV).. Studies comparing bisexual and heterosexual women find that bisexual women are more likely to have never given birth, putting them at greater risk for ovarian and endometrial cancers. (Case, 2004).
We know that smoking significantly increases the risk for lung cancer and many other cancers, including breast cancer. Heavy drinking is linked with cancers of the mouth, throat, liver, breast, colon, pancreas and stomach. Since breast, lung and prostate cancer are among the most common and deadliest cancers, anything that increases the risk for these cancers in a specific population such as bisexuals is cause for concern. We also know that certain sexual behaviors and resulting infections can greatly increase the risk of specific cancers, including mouth and throat cancer and anal cancer. This highlights the need for targeted research and education for both bisexual patients and their health-care providers.
A study based on two large surveys of patients in the U.K. found that the rate of many common cancers within each segment of the LGBT community in England was not significantly higher than that in the larger cisgender and heterosexual population. (Saunders, 2017) Since the U.K. has a National Health Service, it has more universal access to medical care with an emphasis on preventive and public health, and a more consistent system for patient data, than the patchwork private/public health system within the U.S. In addition, the Pew Global Attitudes Project 2013 indicates that sexual identity and gender diversity is more widely accepted in the U.K. than in the U.S., with a 20-plus percentage point spread. All of these factors may influence health outcomes for bisexuals in the U.K. versus the U.S.
But even considering these caveats, the U.K. study found significant differences between cancer rates for bisexuals as compared with heterosexuals. Some of the clearest differences are related to viruses that can be sexually transmitted – HIV, which causes AIDS and weakens the immune system, HSV, which causes herpes, and HPV, strains of which (particularly 16 and 18) cause most cervical cancers, as well as some cancers of the vagina, vulva, penis, anus, rectum, and oropharynx (cancers of the back of the throat, including the base of the tongue and tonsils). While there is a strong general awareness that HPV is a cause of cervical cancer, it’s critical to realize that it causes many other cancers, especially when a person has other risk factors, such as multiple sex partners, heavy smoking and heavy drinking. Bisexual men, many of whom may not be out to their providers, are, therefore, at higher risk for anal cancer.
The human papilloma virus (HPV) can be transmitted through oral, vaginal, or anal sex, putting all sexual orientations and gender identities at some risk. Having multiple partners increases the risk, and studies indicate that bisexuals are highly likely to have multiple sexual partners. The UK study found that, compared to exclusive heterosexuals, bisexual and lesbian women had a greater incidence of oropharyngeal (mouth/throat) cancer, and it is known that this cancer is more likely in those with a history of performing oral sex. Bisexual or gay men had a higher incidence of Kaposi’s sarcoma, which is often seen in HIV-infected individuals, and penile cancer.
Anyone who has receptive anal sex has an increased risk of infection with HPV, and a higher risk of anal cancer. Studies indicate that the rate of anal cancer is increasing among both men and women, and that the screening rate for this cancer is not ideal. (Wilkinson, 2014) (Koskan, 2016) Surveys indicate that bisexual men are less likely to have anal receptive sex, more likely to use female prostitutes, and more likely to have anal sex with women. And bisexual men who are HIV positive or IV drug users are more likely to have unprotected sex, placing them at higher risk of HPV infection.
The UK study also had some unexpected findings regarding other cancers. Bisexual and lesbian women were more frequently seen among those women who had mesothelioma, stomach, and endometrial cancers; bisexual or gay men had a higher incidence of thyroid and oral cancers, melanoma, and Hodgkin lymphoma.
On the healthy, preventive side of the equation, bisexual adults are considerably more likely to engage in physical activity than heterosexuals. Studies of cancer screening have indicated that bisexual women between age 40-64 have a nearly 20% higher rate of mammography than heterosexual women.
Studies indicate the need for increased awareness of the importance of cancer screening. Bisexual women are the least likely to have had a PAP test at any time in their lives. And yet, there is evidence that bisexual women are at much greater risk, as compared to lesbians and heterosexual women, to be diagnosed with a sexually transmitted disease, and more likely to engage in higher-risk sexual behaviors, such as having male partners who also have sex with multiple male partners, including those who are HIV positive, are injecting drug users, or have sex with prostitutes. (Miller, 2007)
These behaviors increase the risk of HPV and HIV infection in bisexual women, and this in turn increases the risk of cervical, mouth, throat, and other cancers. Thus, it is important that bisexual women seek, and that health-care providers strongly recommend, regular PAP testing, and that any signs of mouth or throat cancer be promptly checked and followed up. (Charlton, 2011)
Men of all sexual orientations tend to think that HPV affects only women. However, it is transmitted through all types of sexual activity, so bisexual men, particularly those with multiple partners and those who practice anal receptive sex, should be screened for anal cancer and should be attentive to any signs of the other HPV-caused cancers.
Since we now have an effective vaccine against HPV, all adolescents of every gender identity and sexual orientation should be urged to get this cancer-preventing vaccination. While studies have shown that the earlier 3-dose vaccination was a barrier, the vaccine now requires only two doses and is recommended for everyone between the ages of nine and 26. (Agenor, 2015)
Health-care providers, parents, and young people need more information and education about the importance of the HPV vaccine as a cancer prevention tool. One study that examined the acceptance of a home-based self test for HPV suggests that such a tool may be important for bisexual women, many of whom are less likely to have health insurance or to utilize sexual and reproductive health services. (Reiter, 2015)
Other steps for reducing cancer risks in bisexuals include ensuring that health-care providers include sexual orientation and gender identity questions on intake forms and provide a welcoming environment to encourage disclosure of orientation and identity; and greater education of patients and providers about the relationship between sexual behaviors and specific infection and cancer risks. Health insurers can also link to databases of LGBT-friendly providers to encourage disclosure.(Quinn, 2015)
To improve research on how cancer disparities affect the bisexual population, questions about sexual orientation, gender identity, and the gender of sexual partners needs to be included on medical intake forms, national population surveys and cancer registries. Bisexuality needs to be considered as a distinct category and not simply included with exclusively gay and lesbian individuals as “LGB.”
Several studies have also concluded that there is a need to provider greater support for bisexual cancer survivors. Treatment for cancers of the breast, prostate, anus, throat and mouth may have a greater impact on sexual function in bisexuals than other sexual orientations and require a greater awareness and sensitivity on the part of health-care providers. (Thomas, 2013) (Boehmer, 2014) LGBT cancer survivors report more depression symptoms than their heterosexual counterparts, and bisexuals generally report higher levels of anxiety and depression. (Kamen, 2015)
A comprehensive list of recommendations and information on bisexuality and cancer can be found in the American Society of Clinical Oncology (ASCO) Position Statement: Strategies for Reducing Cancer Disparities Among Sexual and Gender Minority Populations. (Griggs, 2017). This paper was written using the The National LGBT Cancer Action Plan: A White Paper of the 2014 National Summit on Cancer in the LGBT Communities, developed by the National LGBT Cancer Network.