Though there has been an increased focus on LGBT health in recent years, the incidence and risk factors for cancer among LGBT people remain insufficiently studied in countries other than the United States[1]. In most countries, there is scarce high quality statistical information available on LGBT people, as medical systems such as national health and cancer registries do not routinely record diagnoses by sexual orientation. Thus it is not possible to develop estimates that link cancer incidence or mortality to sexual orientation. Consequently, efforts to address cancer disparities associated with sexual orientation are greatly impeded [2, 3]. Other factors contribute to this lack of data. Many LGBT people grew up with legal sanctions on their sexual behaviour and may be reluctant to disclose sexuality in health-related settings, even after homosexuality has been legalised in their country [4]. In a large number of countries, identifying as LGBT remains criminalised and highly stigmatised. Collection of health-related data is close to impossible and as a result there are no data on cancer among LGBT populations available. Due to perceived and actual homophobia, biphobia or transphobia, many LGBT patients do not disclose their sexual orientation to health care providers [5]. Often the issue of sexual orientation is never raised in cancer settings, and the person is presumed to be heterosexual. The current knowledge of cancer risk, incidence and mortality in LGBT communities arises from population based surveys, results from studies of infection-related cancers, in particular HIV, and from clinical, behavioural and epidemiological research. Many studies are small and prone to sampling bias, which limits the generalisability of findings [6]. Obtaining a representative sample of LGBT people is difficult as there is usually no well-defined sampling frame. The recent availability of same-sex marriage registers may offer a new and promising avenue by which a reasonably representative sample may be drawn [7]. As in settings where health care is provided, there may be reluctance to disclose sexual identity in research settings [8, 9]. The LGBT population, like all other populations, is a very heterogeneous group.

It is beyond the scope of this chapter to review all global health policies and legislations as they relate to LGBT communities. An on-line search of policies from Canada, Australia and the United Kingdom, limited to English language documents was undertaken. Search terms included “health”, “policy” “health act” “LGBT”, “lesbian”, “gay”, “government” and “federal”. Examples of policies and legislations in these three countries are discussed below. No national cancer-specific LGBT policies could be identified.

The Australian National LGBTI Health Alliance has estimated that the number of LGBT Australians aged over 65 years will reach 500,000 by 2051 [4]. The Australian Federal Government’s Commonwealth Department of Health and Ageing’s 2012 National Ageing and Aged Care strategy clearly states that LGBT people are a group requiring particular attention due to the past and continuing experience of discrimination. It highlights the limited recognition of LGBT people’s needs by service providers and in policy frameworks and accreditation processes [10]. In the Australian National Women’s Health Policy of 2010, being a lesbian or a bisexual woman is recognised as a social determinant of health. More broadly sexuality, sex and gender identity are also considered to be important determinants of health. The policy declares that for same-sex attracted women, “the fear or experience of insensitive treatment or of blatant discrimination can be a major barrier to accessing appropriate and acceptable health care”. The policy emphasises that in order to minimise the hurdles that same-sex attracted women face when accessing services, it is important to first understand the needs of these groups of women [11].

There are an estimated 3.6 million LGBT people living in UK, approximately 5 % of the population. The UK Health Equality Act (2006) prohibits discrimination on the grounds of sexual orientation in the provision of goods and services, including health care [1]. The 2007 Equality Act (Sexual Orientation) Regulations state there should be equal treatment in all public services, including in the National Health Service [12]. A number of non-governmental organisations have released policies and strategies on health issues, including cancer diagnosis and treatment, affecting LGBT communities in the UK. These documents highlight the need to improve the evidence base on cancer in LGBT communities by conducting more research and the need to eliminate obstacles to healthcare access for LGBT people [1, 13].

In 1996, the Canadian Human Rights Act was amended to explicitly include sexual orientation as one of the prohibited grounds of discrimination [14]. Canada has promoted the equality of same-sex partners, including the legalisation of same-sex marriage in 2005. A question on sexual identity was added to the Canadian Community Health Survey (CCHS) in 2003, which has been very valuable in describing the health and social needs of the Canadian LGBT community. In 2009, 1.1 % of Canadians aged 18–59 reported that they considered themselves to be homosexual (gay or lesbian) and 0.9 % considered themselves to be bisexual [15, 16]. Commentators on the Canadian health system have made observations on the exclusion of LGBT populations from mainstream health promotion research, policy and practice [17]. However, community organisations funded through government sources have worked to develop health promotion programs and policies to increase the visibility of and the services provided to LGBT people [18]. Province-wide guidelines on screening for transgender people for breast, cervical, ovarian, uterine and prostate cancers have been published for British Columbia [19].

In 1989, Denmark became the first country to establish marriage-like partnerships with legal implications for same-sex couples. The largest population-based study of cancer among the LGBT community is a Danish cohort study which linked information from the Danish Civil Registration System on men and women in registered same-sex partnerships with the Danish cancer registry and the Danish AIDS registry. Data were linked for the time period between 1989–1997 and results were compared with the general Danish population. 1614 women and 3391 men in same-sex partnerships were included, with an average follow-up of 4.1 years and 4.6 years respectively. Among women, the overall cancer incidence differed little between women in same-sex partnerships and women in the general population, albeit based on wide confidence intervals (relative risk (RR) 0.9 (95 % CI 0.4–1.9). Men in same-sex partnerships were twice as likely to develop cancer compared with men in the general population. However, this was almost entirely a result of extremely high incidence rates of Kaposi’s sarcoma (KS) (RR 136.0, 96–186), non-Hodgkin’s lymphoma (NHL) (RR 15.1, 10.4–21.4) and anal cancer (RR 31.2, 8.4–79.8). The overall cancer incidence rate was not significantly different when these cancers were excluded from the analysis. Though the findings are pivotal, the study does have a number of limitations. No information was available on sociodemographic factors such as education and income, and the study’s authors caution on how representative participants are of all LGB men and women in Denmark [7]. The sample size was relatively small. Further data from these linked registries from 1982 to 2011 were published in 2013. In this updated study, 0.1 % of all partnerships were same-sex marriages and 1.0 % comprised women and 1.9 % men registering same-sex cohabitation. Cohabitation status was a variable created by determining the number and gender of adults sharing the same address as cohort members. Of concern, all-cause mortality was markedly increased in all age groups in same-sex married women (hazard ratio (HR) 1.89, 95 % CI 1.60–2.23) compared with opposite-sex married women, with the greatest differences seen in cancer (HR 1.62, 95 % CI 1.28–2.05) and suicide related mortality (HR 6.4). The mortality rates of men in same-sex marriages had declined since the 1990s. Though still raised when compared with opposite-sex married men, the mortality rates were similar to those among unmarried, widowed or divorced men [20].

Other population-based surveys include the national Canadian Community Health Survey (CCHS). Since 2003, respondents have been asked if they are heterosexual, homosexual (lesbian or gay) or bisexual. In cross-sectional analyses of results for women (60937 heterosexual, 354 lesbian and 424 bisexual), lesbian and bisexual women were more likely to smoke than heterosexual women (odds ratio (OR) 1.77, 95 % CI 1.22–2.57 and 2.04, 95 % CI 1.47–2.83 respectively). Lesbian and bisexual women were twice as likely to report excess alcohol consumption compared with heterosexual women (OR 2.67 (95 % CI 1.67–4.28) and 2.00 (95 % CI 1.30–3.09) respectively) [15]. Gay and bisexual men in the 2003 CCHS had similar rates of daily smoking or excess alcohol consumption as heterosexual men [16].

A national Dutch survey of patients attending general practices was conducted in 2001.19685 people were approached and 65 % participated. Sexuality was reported by 98.2 % of 9684 participants, with 0.6 % identifying as bisexual men, 1.5 % as gay men, 1.2 % as bisexual women and 1.5 % as lesbian women. The SF36 questionnaire, a standardised measure of functional health and wellbeing, was administered and results demonstrated lower acute and general mental health status in LGB people. Cancer rates were not reported. In this study, sexual orientation was not linked to current cigarette smoking in men or women. A lower proportion of LGB people were currently using alcohol, but those who currently used alcohol were more likely to report recent excess consumption (adjusted OR 1.72, 95 % CI 1.17–2.99) [21]. Private Lives 2 is the second national Australian on-line survey of health and well-being of LGBT Australians. It was administered in 2011, with 3835 respondents completing the survey. According to results from the SF36 questionnaire, the general health of male respondents was lower than the national average. The general health of female respondents was lower still, and transgender men and women reported the lowest levels of general health. Only a small numbers of cancers were reported (2.1 % of respondents in total; 2.4 % men, 1.8 % women, 2.5 % transgender women, 0 % transgender men). The most common cancers were skin (19 cases), prostate (16 cases) and breast cancer (12 cases). Of note, breast cancer screening rates did not appear to be lower, with 56.2 % of women aged 50–69 years reporting having a mammogram in past 2 years compared with 55.2 % of similar-aged women in the general population [22].

Much of the existing research and proposed evidence for cancer disparities among LGBT communities is based on differing rates of risk factors for cancer. Behavioural factors such as cigarette smoking and excess alcohol consumption have been associated with a number of cancer types. Nulliparity and being overweight or obese have been associated with breast cancer. Chronic HPV infection has been causally linked with cervical and other ano-genital cancers and cancers of the head and neck (particularly the oropharynx and tonsil). A number of these risk factors, including behaviours and infectious agents, are discussed here.

It is evident that information and data on cancer rates and mortality are far more extensive for gay men with HIV than for LGBT people in general [44]. This is due primarily to the presence of HIV and AIDS registries, which often capture information on sexual behaviours, at least among men diagnosed with HIV. Though an exhaustive review of published literature in this area is beyond the scope of this chapter, the studies discussed here consistently demonstrate the increased risk of cancer among gay and bisexual men living with HIV. In a Scottish study of data linkage from cancer and HIV registries from 1981 to 1996, the incidence of cancer among people living with HIV was 11 times higher than the general population. Among gay and bisexual men, the incidence of cancer was 21 times higher than men in the general population (standardised incidence ratio (SIR) 21.4, 95 % CI 17.4–26.1) [45]. In a Spanish study linking AIDS and cancer registry data, compared with other people living with HIV, MSM and MSWM had the highest rates of Kaposi’s sarcoma (SIR 3003.23) and any invasive cancer (SIR 53.94) and the second highest rates of non-Hodgkin’s lymphoma (after heterosexual men living with HIV, SIR 240.66) [46]. Combined data from 1997 to 1998 on cancer rates among 8385 men (25.8 % homosexual) from two hospital HIV cohorts and a cohort of HIV seroconverters in Italy and France were studied. Observed cancer rates among MSM were compared with expected rates (derived from rates in men in the general population). There were markedly increased observed rates of cancer at any site (SIR 44.2), Kaposi’s sarcoma (SIR 2055), cancer of the salivary glands (SIR 65.5), non-Hodgkin’s lymphoma (SIR 124) and Hodgkin’s disease (SIR 11.2) [47].