5 November 2008
British scientists have developed a new test to detect early signs of
anal cancer, which will potentially save thousands of lives.
The incidence of anal cancer is estimated as 37 per 100,000 in gay
men, which is similar to the rate of cervical cancer in women before
the introduction of pap smear screening. For gay men who are
HIV-positive, the incidence is about twice as great – around 75 per
100,000.
The study, funded by the UK's Medical Research Council (MRC) and
Cancer Research UK, is published in the American journal, Cancer
Epidemiology Biomarkers and Prevention.
See the full MRC news release below.
Lead author of the study, Dr Nick Coleman, said: "We have uncovered a
more effective way to detect anal cancer in its early stages, meaning
fewer people would have to undergo the rigours of radiotherapy and
chemotherapy treatment.
"Anal cancer is a difficult disease to detect and many cases are
identified after it becomes too late for people to undergo simple
surgery to remove it. We wanted to create a test which was easier to
perform and had a high rate of accuracy. This study suggests that MCM
testing fits the bill very well indeed."
Gay human rights campaigner Peter Tatchell, who in 2003 successfully
lobbied the UK government to take action on anal cancer, said:
"This new screening test is likely to save thousands of lives by
ensuring earlier diagnosis and treatment. The Cambridge medical team
have done magnificent, life-saving work. I offer them my
congratulations and appreciation."
"Two decades ago, I deduced that if the Human Papilloma Virus (HPV)
causes cervical cancer in women, it must also have the potential to
cause anal cancer in people who have anal sex, especially gay and
bisexual men.
"I lobbied the UK government for two decades to take action but was
constantly rebuffed. The British Medical Journal and The Lancet
declined to report the issue and Cancer Research UK dismissed it.
Everyone said there wasn't enough credible research to justify action.
But that was why I was urging research, in order to establish the
incidence and risk, and devise screening methods and treatment
protocols.
"From the mid-1990s, I stepped up my prodding of the medical
establishment. I wrote to successive Health Ministers and STI
specialists, urging the introduction of anal pap smears of at risk
populations and the funding of research programmes. The replies were
dismissive and illogical; typically arguing that the science on this
issue was "uncertain".
"This was a limp justification for doing nothing. If the medical
knowledge was inadequate, I argued this was all the more reason to
fund pilot studies.
"Undeterred, I collated fragments of US research showing that pap
smears could be an effective screening tool for anal cancer, and that
screening is cost-effective and can save lives.
"In 2003, I lobbied the then newly appointed Health Secretary, Dr John Reid.
I advised him: 'Screening has massively reduced deaths from cervical
cancer. A similar screening programme among men and women who have
anal sex could also identify cancerous and pre-cancerous
irregularities; ensuring earlier treatment and enhanced survival. It
cannot be medically justifiable to treat people at risk of anal cancer
differently from those at risk of cervical cancer'.
"My letter urged the Department of Health to fund pilot studies at STI
clinics, including anal pap smear screening programmes to detect the
prevalence of HPV infection and anal cancer among risks groups such as
gay and bisexual men.
"Dr Reid immediately referred my letter to the National Screening
Committee (NSC). Within two weeks the NSC met and agreed 'the existing
evidence should be reviewed and assessed', with a view to funding
'further research'.
"An evaluation project was established by Dr Muir Gray of the NSC.
Following a seminar of experts at the British Medical Association
headquarters, two working groups were formed to examine future
research avenues, the viability of screening programmes and the
development of new experimental therapies.
"This has resulted in the coordination and cross-referencing of anal
cancer research and treatment throughout the UK, including new
therapies and test methods, such as the new diagnostic method devised
by the Cambridge team," said Mr Tatchell.
See the full MRC news release below.
Further information:
Peter Tatchell –
020 7403 1790
Medical Research Council – News Release
Immediate
A new 'smear test' to prevent anal cancer
Scientists at the Medical Research Council (MRC) have found a new and
improved technique to detect anal cancer that may cause the number of
people dying from the disease to drop significantly.
The research, carried out at the MRC Cancer Cell Unit in Cambridge,
explores using minichromosome maintenance proteins (MCMs) to detect
pre-cancerous and cancerous cells in the anus. The study, funded by
the MRC and Cancer Research UK, is published today in the American
journal Cancer Epidemiology Biomarkers and Prevention.
MCMs have been used to find pre-cancerous and cancerous cells in other
areas of the body more accurately and effectively but this is the
first time they have been used to detect anal cancer.
Lead author of the study, Dr Nick Coleman, said: "This is welcome news
for people who are at high risk of developing anal cancer. We have
uncovered a more effective way to detect anal cancer in its early
stages, meaning fewer people would have to undergo the rigours of
radiotherapy and chemotherapy treatment.
"Anal cancer is a difficult disease to detect and many cases are
identified after it becomes too late for people to undergo simple
surgery to remove it. We wanted to create a test which was easier to
perform and had a high rate of accuracy. This study suggests that MCM
testing fits the bill very well indeed."
The study first involved screening anal tissue samples from different
patients to pick up the biological differences between normal cells
and cancer cells. The scientists found that normal tissue lacked MCMs
whereas anal cancer and pre-cancer had an abundance of MCMs. The power
of MCM testing was then shown in an independent group study of 235
anal smears from 144 subjects.
The test successfully identified 84% of the patients with anal
pre-cancer, without producing a high rate of false alarms in people
without disease.
Dr Coleman said: "This is a much better overall performance than
existing methods of detecting anal disease, which either miss too many
cases or show up as positive when no disease is actually there. MCM
tests can also be read by a computer, which would avoid the risk of
human error and be a cheaper option too."
Dr Lesley Walker, director of cancer information at Cancer Research
UK, said: "MCMs are already showing promise as early markers to be
used in screening for a number of cancers, so it is encouraging to see
this research progressing.
"We must also continue to raise awareness of the disease, particularly
among people in high risk groups such as gay and bisexual men so they
can take action if they have symptoms."
The incidence of anal cancer is estimated as high as 37 per 100,000 in
gay men and about double if they are also HIV-positive.
Human rights campaigner Peter Tatchell has lobbied for anal cancer
screening and treatment programmes targeted at the higher risk gay
community for many years.
He said: "For gay and bisexual men who are at risk of anal cancer,
these tests are an important medical breakthrough. They will help save
lives. With this reliable screening test, signs of anal cancer will be
detected earlier, leading to speedier, more effective treatment."