ASHM 2008: Immune deficiency driving growth of anal cancer

Unlike many diseases that have disappeared with the advent of HAART [1]Highly Active AntiRetroviral Therapy ??? aggressive treatment of HIV infection using several different drugs together., anal cancer has not, with rates in HIV-positive gay men now sitting at 1 in 1000, which is greater than rates of cervical cancer. Professor Joel Palesky from the University of California in San Francisco presented a theory on the high rates, suggesting that HIV-associated immune deficiency was driving the conversion of the human papilloma virus (HPV) to high-grade anal lesions and that the progression is related to acquired genetic changes rather than HIV itself.

A high proportion of gay men have contracted HPV in their earliest sexual encounters in one form or another but it is the particular strain [2][HIV strain] Any subgroup of the HIV species. Because HIV mutates very easily, there are many different strains (and may be multiple strains within a single person). of HPV known as HPV-16 which is the most likely to become cancerous. Most anal warts are caused by HPV-6 and HPV-11. Usually the infection remains benign but a number of factors increase the chance of developing anal cancer later in life: these include immune deficiency and smoking. This has been extrapolated from findings that vaginal secretions of women who smoke have been found to block the immune function of the cells in the cervix.

It would be commonsense to expand the current vaccination program for young women to prevent cervical cancer to include young gay men at risk, the conference was told but it would be 50 years before we would see any benefit. Dr Nolan emphasised three preventive courses of action: effective HIV treatment, checking for oncogenic viruses [3]A small infective organism which is incapable of reproducing outside a host cell. and stopping smoking.