A New 'Smear Test' to Prevent Anal Cancer

Scientists at the Medical Research Council (MRC) have found a new andimproved technique to detect anal cancer that may cause the number ofpeople 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 detectpre-cancerous and cancerous cells in the anus. The study, funded bythe MRC and Cancer Research UK, is published today in the Americanjournal Cancer Epidemiology Biomarkers and Prevention.

MCMs have been used to find pre-cancerous and cancerous cells in otherareas of the body more accurately and effectively but this is thefirst time they have been used to detect anal cancer.Lead author of the study, Dr Nick Coleman, said: "This is welcome newsfor people who are at high risk of developing anal cancer. We haveuncovered a more effective way to detect anal cancer in its earlystages, meaning fewer people would have to undergo the rigours ofradiotherapy and chemotherapy treatment.

"Anal cancer is a difficult disease to detect and many cases areidentified after it becomes too late for people to undergo simplesurgery to remove it. We wanted to create a test which was easier toperform and had a high rate of accuracy. This study suggests that MCMtesting fits the bill very well indeed.

"The study first involved screening anal tissue samples from differentpatients to pick up the biological differences between normal cellsand cancer cells. The scientists found that normal tissue lacked MCMswhereas anal cancer and pre-cancer had an abundance of MCMs. The powerof MCM testing was then shown in an independent group study of 235anal smears from 144 subjects.

The test successfully identified 84% of the patients with analpre-cancer, without producing a high rate of false alarms in peoplewithout disease.

Dr Coleman said: "This is a much better overall performance thanexisting methods of detecting anal disease, which either miss too manycases or show up as positive when no disease is actually there. MCMtests can also be read by a computer, which would avoid the risk ofhuman error and be a cheaper option too.

"Dr Lesley Walker, director of cancer information at Cancer ResearchUK, said: "MCMs are already showing promise as early markers to beused in screening for a number of cancers, so it is encouraging to seethis research progressing.

"We must also continue to raise awareness of the disease, particularlyamong people in high risk groups such as gay and bisexual men so theycan take action if they have symptoms.

"The incidence of anal cancer is estimated as high as 37 per 100,000 ingay men and about double if they are also HIV-positive.

Human rights campaigner Peter Tatchell has lobbied for anal cancerscreening and treatment programs targeted at the higher risk gaycommunity 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 savelives. With this reliable screening test, signs of anal cancer will bedetected earlier, leading to speedier, more effective treatment."