A Hong Kong study found that almost 30% of healthy middle-aged and elderly adults had bowel tumours that could develop into cancer, researchers said.
Experts at the Chinese University carried out colonoscopy screening on 3,343 people aged between 50 and 70 who showed no symptoms of bowel cancer between May 2008 and June 2009.
A total of 985, or 29.5%, were diagnosed as having adenoma or advanced neoplasm - types of benign tumours or polyps which have the potential to develop into cancer. All had the polyps removed.
Of the others, 12, or 0.5%, were found to have cancer and one subsequently died of the disease.
The researchers say the findings back up the case for the government to introduce bowel cancer screening for people aged over 50 arguing it has the potential to save many lives.
Western diets the culprit
Professor Francis K L Chan of the Jockey Club Bowel Cancer Education Centre said only three patients developed complications after colonoscopy and all recovered.
"This reflected that bowel cancer screening is a safe procedure with low complication rate," Chan said.
Bowel cancer, also called colorectal cancer, is now the second biggest cancer killer in Hong Kong, causing the deaths of 1,500 people every year. Often it is only diagnosed when symptoms occur in the more advanced stages.
Some experts have attributed the rise in bowel cancer to increased Westernised diets that are high in animal fats and meat.
At the moment, the government only funds screening for those at high risk such as those with a family history or previous history of bowel cancer. Screening at private clinics costs in the region of R6 050.
(Sapa, September 2011)