By Associate Professor Jonathan Hallett, Dr Jenny McCloskey and Dr Daniel Vujcich, Curtin University
Despite Australia’s world-leading initiatives in HPV prevention, a critical gap remains in our healthcare approach that requires urgent attention. This is the disproportionate burden of anal cancer among gay, bisexual, and other men who have sex with men (GBMSM).
The incidence of anal cancer in Australia has increased significantly, rising by an average of 3.4% annually since 2010. GBMSM experience up to 20 times higher risk compared to the general population – comparable to cervical cancer rates in women prior to the implementation of screening programs.
For GBMSM living with HIV, this risk is further elevated to more than 60 times higher than the general population.
HPV infection constitutes the primary cause of anal cancer, with significantly higher prevalence among GBMSM compared to heterosexual men. Research demonstrates that persistent HPV infection, particularly with HPV16, is strongly associated with reduced clearance of high-grade anal intraepithelial neoplasia.
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A study reported that HIV-positive GBMSM exhibited significantly lower HPV clearance rates compared to HIV-negative GBMSM across multiple HPV genotypes. Furthermore, evidence indicates that treatment of high-grade anal intraepithelial neoplasia can reduce anal cancer incidence.
The protection gap
Australia pioneered HPV vaccinations with school-based programs for girls commencing in 2007 and boys in 2013-14. While these initiatives have dramatically reduced HPV prevalence in younger cohorts, they created a significant protection gap for adults who were beyond school age when the programs were implemented.
Although vaccination against HPV is recommended for GBMSM up to age 45 in Australia’s immunisation guidelines, it is not funded through the National Immunisation Program for individuals over 26 years, creating a substantial barrier to uptake.
In Western Australia, certain healthcare providers have administered HPV vaccination “off-label” to GBMSM aged over 35 years, creating a natural experiment to evaluate vaccine effectiveness in this population.
Current evidence on HPV vaccine efficacy in adults with prior HPV exposure remains limited, though studies examining vaccination in non-HPV naive GBMSM have shown promising results.
Knowledge and attitude barriers
Knowledge deficits further compound this issue. In 2019 it was reported that most HIV-positive (51.8%) and HIV-negative (68.1%) GBMSM underestimated their risk of anal cancer, with only 12.5% reporting ever having discussed anal cancer with their healthcare provider.
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Understanding of the relationship between HPV infection and anal cancer remains generally poor.
Late-stage detection exacerbates poor outcomes. Factors contributing to delayed diagnosis include the absence of formal screening programs, stigma surrounding anal symptoms, and negative experiences with healthcare providers. These barriers directly translate to poorer outcomes and higher mortality rates.
A path forward
Healthcare professionals need to address these gaps with urgency. Several evidence-based approaches warrant immediate attention:
- Expansion of funded access to HPV vaccination for adult GBMSM irrespective of age is necessary. Current age-based funding restrictions create an artificial barrier to prevention unsupported by clinical evidence.
- Implementation of targeted education campaigns would increase awareness among both GBMSM and healthcare providers. Many practitioners may be inadequately informed about elevated risk factors or uncomfortable discussing anal health, perpetuating knowledge gaps.
- Implementation of the recently Released Anal Cancer Screening Guidelines for people living with HIV (2025) from the Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM). These provide a crucial framework for systematic screening and recommend that gay, bisexual and other men who have sex with men and trans women living with HIV over age 35, as well as other people living with HIV over age 45, should be offered primary high-risk HPV testing with cytology triage every three years for those who test negative for high-risk HPV.
- Self-sampling methods for HPV testing demonstrates significant potential. Recent research has validated that self-collection of anal specimens shows high concordance with clinician-collected samples.
Key messages
- There is a disproportionate burden of anal cancer among gay, bisexual and other men who have sex with men (GBMSM)
- Expanding vaccination access, improving education, and implementing systematic and innovative screening approaches, can prevent suffering and save lives
- GBMSM patients deserve comprehensive attention to this preventable cancer burden.
Author competing interests – nil
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