Health promotion update: The Bottom Line: HPV, gay men and anal cancer

Human papillomavirus (HPV) is the most common sexually transmitted infection (STI). Most sexually active people come into contact with it at some time in their lives. HPV causes common warts, genital warts and a range of cancers, including cancers of the anus, cervix, penis, vagina, vulva, and the neck and throat.

Gay men (and particularly HIV-positive gay men) are at a greater risk of developing some HPV-related cancers, compared to the general population. Other people at an increased risk of anal cancer include women with previous anal or genital HPV disease, organ transplant recipients and HIV-positive women and men (that are not men who have sex with men [MSM]).

MSM are about 20 times more likely than heterosexual men to develop anal cancer, and HIV-positive MSM are even more likely (up to 100 times more than the general community). Gay men over 35 and HIV-positive gay men are at greater risk of cell changes progressing to anal cancer. Anal cancer is one of the most common cancers for people living with HIV.

There are vaccines available to protect against acquiring HPV, including the two strains of HPV that cause the most anal cancers. The most commonly used vaccine also protects against two main strains that cause anal and genital warts. The vaccine is most effective if given prior to exposure to HPV. However, some research has shown that even if someone has had prior HPV exposure, they may still derive some benefit from vaccination.

If someone has already been exposed to one or more of the HPV strains against which the vaccine is targeted, they may still potentially benefit from the vaccine by protection against other strains which they have not yet been exposed to. In people with evidence of prior infection of the vaccine strains, vaccination can possibly help protect from reacquisition or recurrence of infections of these strains that could lead to warts and other cell changes, including cancer.

There are currently no widely accepted clinical guidelines for doctors on anal screening. At the moment, there is insufficient understanding of how anal cancer progresses from the early stages, which lesions are most likely to develop, and which treatments are most effective. Research projects are being conducted in Australia now to see what these guidelines might be. Information on these research projects are detailed with this article.

Although there are not yet widely accepted clinical guidelines for anal screening, many clinicians believe early detection through anal screening is the right approach. What is clear is that there are advantages in people knowing that they have early signs of anal changes – which may or may not progress – and to ask their doctor to keep monitoring for changes in the anus. This is particularly the case for gay men over 35 and HIV-positive gay men. Early detection greatly increases the chances of survival.

Until screening guidelines are determined asking your doctor for digital anal-rectal examinations (DAREs) can be an important way to detect for early signs of anal cancer.

DAREs involve the doctor inserting a lubricated finger into the anus to check for changes. As this is a relatively new field, it may be best for people to go to a doctor that sees a lot of gay men or a sexual health clinic to speak to them about getting a DARE. Information for clinicians on the training to perform DAREs are detailed in the breakout box at the end of this article.

In response to gay men (and particularly HIV-positive gay men) at greater risk of developing anal cancer, the Australian Federation of AIDS Organisations (AFAO) has recently launched The Bottom Line, a new nation-wide campaign for gay men and other men who have sex with men on HPV and anal cancer.

The campaign has been designed to increase gay men’s knowledge in relation to HPV, the impact of HPV and related cancers, screening procedures for anal cancer, and vaccinations available to reduce the risk of HPV infection and related cancers.

The Bottom Line is based around a
website (www.thebottomline.org.au) and is supported by a range of materials including posters, a booklet on understanding anal cancer screening results, a booklet for men diagnosed with anal cancer, and a range of advertisements.