Screening 55 to 64-year-olds with an examination of the lower colon and rectum using a small camera can cut death rates from colorectal cancer by 43 percent, according to British scientists.

Colorectal cancer is the third most frequently diagnosed cancer worldwide, accounting for more than a million cases and around 600,000 deaths every year.

Beating the disease is strongly linked to how early it is detected, with survival rates of around 90 percent for cancers that are found early and have not spread.

Many developed countries have introduced screening programmes using a faecal occult blood test, which can detect early cases and reduce death rates by around 15 percent.

But Wendy Atkin from Imperial College London and Jane Wardle from University College London said their study showed more lives, and money, could be saved if screening used sigmoidoscopy - a small, flexible camera that is inserted into the rectum.

“Economic analyses suggest ... a once-only flexible sigmoidoscopy screen at age 55 or 60 years would be cost saving, largely because of the avoided costs of treatment,” they wrote.

Some of the newest drugs in colon cancer - such as Roche’s Avastin, Vectibix from Amgen, and Erbitux from Merck KGaA - can cost thousands of euros a month.

Atkin said in a telephone interview her conclusion that sigmoidoscopy screening would save money was based on previous studies showing it was cost effective in preventing the need to treat so many patients with such expensive medicines.

“There’s a real problem about the affordability of these drugs,” she said. “But one way to make them more available is to reduce the numbers who develop these cancers with screening.”

Cancer screening programmes in developed nations have come under close scrutiny in recent months with some European studies suggesting national breast cancer screening programmes do little to reduce death rates and research in the United States showing that prostate cancer screens lead to widespread overdiagnosis.

Commenting on the study, which was published in The Lancet medical journal, David Ransohoff of the University of North Carolina said the findings showed that for this test and this type of cancer, screening appeared to be well worth while.

“The good news is that this size of benefit is large for any cancer screening test, certainly compared with mammography for breast cancer or assay of prostate-specific antigen (PSA tests) for prostate cancer,” he wrote.

The researchers analysed data from more than 170,000 men and women from 1994 to 1999 at 14 health centres across Britain and then followed the patients’ progress.

Most colorectal cancers start from adenomas, often symptomless growths that develop in 20 to 30 percent of the population. Two-thirds of colorectal cancers and adenomas are in the rectum and lower colon, which can be detected early by flexible sigmoidoscopy.

Among those who attended screening, rates of colorectal cancer were cut by 33 percent and death rates from the disease were cut by 43 percent, they said. This means one colorectal cancer death is prevented for every 489 people screened.

SOURCE: Lancet, online April 27, 2010.