Philadelphia, PA, October 1, 2007 Two studies in the October issue of the journal Gastroenterology may help in refining recommendations for the use of colonoscopy to screen for colorectal cancer.
One study reports that patients with large polyps or adenomaspre-cancerous growths that may develop into colorectal cancerson initial colonoscopy may need more frequent follow-up, while those with only a few small polyps can be screened less often. The second study suggests that relatives of patients with large polyps should also be targeted for screening.
Dr. David A. Lieberman and colleagues of the Department of Veterans Affairs (VA) Medical Centers in Portland, Ore., compared the results of follow-up colonoscopy in two groups of patients. One group of 895 patients had some type of colorectal neoplasiapolyps or cancersdetected on their initial colonoscopy. The other 298 patients had no polyps or cancers.
When colonoscopy was repeated five years later, advanced polyps or cancers were found in approximately seven percent of the patients with previous polyps, compared to two percent of those without previous polyps.
The "more severe" the abnormalities at initial colonoscopy, the greater the likelihood of detecting large polyps (ten millimeters or larger) or cancers at follow-up. The risk was five times higher for patients with three or more small polyps and six to seven times higher for those who had large polyps or polyps with certain pre-cancerous changes (villous adenoma or high-grade dysplasia). For patients with one or two small polyps, there was no significant increase in risk.
The second study, led by Vanessa Cottet, M.Sc., of Universit de Bourgogne, France, asked whether family members of patients with large polyps were more likely to have abnormal results on colonoscopy. Large polyps or colorectal cancers were found in about eight percent of 168 first-degree relativesparents, children, or siblingsof patients
|Contact: Jayne Dawkins|