Research conducted by the Kirby Institute at UNSW (formerly the National Centre in HIv epidemiologyThe branch of medical science that deals with the study of incidence and distribution and control of a disease in a population. and ClinicalPertaining to or founded on observation and treatment of participants, as distinguished from theoretical or basic science. Research) has shown that the annual incidence of anal cancer in Australia has increased by almost 50% in the last 20 years.
What’s more, the rate of increase has been twice as fast for men, about 20 times higher for gay men and even higher for those with HIV. In fact, overseas data suggests that up to one in a 1000 positive gay men per year may develop the disease.
More than 80% of anal cancer is caused by a type of human papillomavirus, HPV16, which is preventable by the currently available HPV vaccines (Gardasil or Cervarix) that are currently offered for free in Australia to girls and young women to prevent cervical cancer. The vaccines are most effective when given to children, before the start of sexual activity, but unfortunately they are not funded for male vaccination.
Last month, the Pharmaceutical Benefits Advisory Committee (PBAC) rejected an application by the vaccine’s manufacturer, CSL, to fund vaccination coverage for school-aged boys. According to minutes from the March meeting, the PBAC rejected the submission because of unacceptably high and uncertain cost-effectiveness(Of a drug or treatment). The maximum ability of a drug or treatment to produce a result regardless of dosage. A drug passes efficacy trials if it is effective at the dose tested and against the illness for which it is prescribed. In the standard procedure, Phase II clinical trials gauge efficacy, and Phase III trials confirm it..
It is likely that a new application for funding of vaccination of boys will be submitted later this year.
HPV is easily transmitted through sexual contact.
Studies conducted by the Kirby Institute have shown that almost all gay men in Sydney have anal infection with this virus, and about 30% carry the particular high-risk type, HPV16, in the anus.
Anal cancer is mostly asymptomatic in its early, easily treatable stages. In the later stages the chance of survival is poor because the disease has already spread.
It is hoped that screening may detect precancerous lesions which can be treated and thus prevent anal cancer; or allow the detection of anal cancer at its very early stages when survival rate is very high.
At this time, there are no guidelines as to who should be screened and how often.
There are many questioned to be answered before routine anal cancer screening can be recommended.
The SPANC study, currently underway at the Kirby Institute and St Vincent’s Hospital in Sydney aims to answer these questions. So far, close to 100 HIV positive and negative gay men have joined the three-year-long cohortIn epidemiology, a group of individuals with some characteristics in common. A cohort study is a special kind of clinical trial which looks at a treatment or treatment strategy in a cohort of people. study. But more are needed.
Information, including how to participate, can be found at the study website www.spanc.org.au