Researchers studied 106,000 men and women aged between 60 and 64 across Finland to examine the effectiveness of a colon cancer screening programme started in 2004 in which faecal samples are analysed for blood.

Blood traces can be an indicator of cancer.

Colorectal, or colon and rectal, cancer is the second most fatal form of cancer in Europe and the United States.

The team found that the test identified four out of ten colon cancers, enough to say the programme was successful.

'The sensitivity of the Finnish screening programme for colorectal cancer at the first round was adequate even if relatively low,' the researchers wrote in the British Medical Journal.

'Programme sensitivity in Finland was sufficient to justify continuation of the programme.'

The findings suggest that similar programmes introduced in about 50 countries may be working.

In the United States, men are advised to begin regular colonoscopies at the age of 50. But the procedure, in which a flexible lit tube is passed through the bowel, can be costly, uncomfortable and harmful for a patient.

National health systems are beginning to adopt a simpler test in which doctors analyse a faecal sample for blood.

Previous studies looked chiefly at how well the tests worked in clinical trials rather than investigating a screening system already up and running, said Dr Nea Malila of the Finnish Cancer Registry, who led the study.

'This seems to be working in a public health setting as well as it did in trials,' she said in a telephone interview. -- REUTERS