Colon cancer should be screened periodically once in 5 years in older people (above 50).The usual test is the fecal occult blood test (FOBT) which looks for traces of blood shed by a tumour, or the sigmoidoscopy - an examination of the lower colon. According to researchers at the Finland Affairs Medical Centre in the US, death rate from colon cancer has been decreased due to the routine screening.
They investigated over 3,000 apparently healthy male volunteers aged between 50 and 70 and gave them a colonoscopy to detect any tumours. In comparison to the sigmoidoscopy, colonoscopy is much more effective because it enables to look at the whole colon.
FOBT could detect fewer than 25% of precancerous colon growths in people with no symptoms, while one-time sigmoidoscopy detected 70% of growths. After completing both the tests the detection rate up to 76 %. The researchers feel that people need to follow-up and repeat testing to be sure they have caught a cancer in time.
The problem was worse for people over 60, as they are more likely to develop a cancer in the upper colon where it could more easily be missed. The researchers suggest that older people should be offered colonoscopy as a routine screen, even though it is more expensive. They also added that this research should be repeated among women too, since they tend to develop colon tumours later in life than men.
Source : Journal of Medicine August 2001