Family history of colorectal cancer justifies colonoscopy
14 March 2003
People with a first-degree relative who has had a bowel polyp, specifically a colorectal adenoma, should undergo surveillance colonoscopy because their risk of polyps or cancer is doubled, according to a new recommendation from The Gut Foundation.
While the advice conflicts with National Health & Medical Research Council (NHMRC) screening guidelines for colorectal cancer, it is consistent with new guidelines from the American Gastroenterological Society recommending colonoscopy at age 40 if there is a positive family history of colorectal cancer or polyp (Gastroenterology 2003; 124: 544-60).
However, unlike the US, which recommends screening first-degree relatives of those who had a polyp at younger than 60 years of age, The Gut Foundation recommends screening relatives regardless of the age of the affected person.
Gut Foundation president Associate Professor Terry Bolin said broadening the existing recommendation to include family history of adenomas as well as cancer was Medicare funded because the person had higher than average risk.
He said the recommendation was based on cumulative evidence and applied to people whose close relative had a colorectal adenoma, rather than a hyperplastic polyp.
(Colorectal adenomas and hyperplastic polyps are the 2 most common types of benign growths arising from the surface of the large bowel or rectum. Doctors believe that adenomas may indicate a risk of later bowel cancer, whereas hyperplastic polyps are less likely to indicate this risk.)
'If a person's father or mother had one [a colorectal polyp], then when this person reaches 40 they should have a colonoscopy.'
'If a child has an adenoma, their parents should have a colonoscopy,' Professor Bolin said.
If colonoscopy is clear, a repeat is not needed for 5 years, with moves to extend this to 10 years, he said.
The recommendation is contained in the foundation's new information booklet, Colorectal Cancer Prevention, Diagnosis & Treatment and new patient information leaflet Bowel Cancer, Am I at Risk?.
However, Gastroenterological Society of Australia (GESA) chair Dr Katie Ellard said GESA would stick with NHMRC guidelines on screening for colorectal cancer.
She said there were many views and while The Gut Foundation was more aggressive in its screening recommendations, NHMRC guidelines were more conservative.
'People should be allowed to examine epidemiological [population health] information on the fact polyps can increase risk and make a choice themselves,' she said.
Last Reviewed: 17 March 2003
- 1. Medical Observer Weekly 14/03/03
