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European governments should divert funds to routine bowel cancer tests from less effective breast and prostate screening programs, scientists said on Saturday, presenting what they called "irrefutable" evidence that bowel screening saves lives.
Many governments devote significant funds to breast cancer screening, but studies in recent years have found that routine breast mammograms can also lead to so-called "over diagnosis" when tests pick up tumours that would not have caused a problem. And a new study presented at the European Cancer Conference (ECC) in Amsterdam at the weekend showed men experience more harm than good from routine prostate cancer screening tests.
In bowel cancer screening, however, the risk of over-diagnosis is very low, while gains in terms of reducing deaths are large – making routine testing cost-effective, Philippe Autier, a professor at France's International Prevention Research Institute (IPPR), told the conference."There is now an irrefutable case for devoting some of the resources from breast and prostate cancer screening to the early detection of colorectal (bowel) cancer," he said.
A large European study published last year found that breast screening programmes over-diagnose about four cases for every 1000 women aged between 50 and 69 who are screened.
The IPPR's research director Mathieu Boniol, who studied the impact of prostate screening, said his results showed routine use of prostate-specific antigen (PSA) tests creates more harm in terms of incontinence, impotence and other side-effects from prostate cancer treatments than benefit in terms of detecting life-threatening cancers. "PSA testing should be reduced and more attention should be given to the harmful effects of screening," he told delegates.
Reductions in death rates
Meanwhile, results of a study conducted by Autier using data from 11 European countries between 1989 and 2010 showed that the greater the proportions of men and women routinely screened for bowel cancer, the greater the reductions in death rates.
Colorectal cancer kills more than 600 000 people a year worldwide, according to the World Health Organisation. In Europe some 400 000 people are diagnosed with the disease each year. In Austria, for example, where 61% of those studied reported having had colorectal screening tests, deaths from this form of cancer dropped by 39% for men and 47% for women over the decade.
Meanwhile in Greece, where only 8% of males had had bowel cancer screening, death rates rose by 30% for men. In the light of the results, Cornelis van de Velde, an oncologist at Leiden University Medical Centre in the Netherlands and president of the European Cancer Organisation, said it was "very disappointing" there are such wide differences in European governments' approaches to colorectal screening.
"People over 50 should be informed of the availability of the test, and pressure should be put on national health services to put more effort into organising screening programs," he told the conference.
Screening for early signs of bowel cancer involves either a faecal occult blood test, which checks a sample of faeces for hidden blood, or endoscopy, where a tiny camera is introduced into the large bowel to look for the polyps that can be a precursor of cancer. In some European countries, such as France, Germany and Austria, many men and women over the age of 50 have regular colorectal screening examinations, while in others, such as The Netherlands and Britain, screening is much less common.
