Detection of Serrated Colorectal Polyps

Research teams led by Mayo Clinic have demonstrated for the first time that that stool DNA testing may be useful for detection of an important type of colorectal pre-cancer called serrated polyps. The findings were presented at Digestive Disease Week 2010, the annual meeting of the American Gastroenterological Association.
David Ahlquist, M.D., a gastroenterologist with Mayo Clinic and the senior investigator, said that sensitive stool DNA test methods developed at Mayo Clinic can detect common forerunners of colorectal cancer. Detection of precursor lesions during screening is essential if cancer prevention is the goal, Dr. Ahlquist says.
Compared to widely used fecal blood tests, stool DNA testing has higher detection rates for curable stage colorectal cancer and for common precancerous polyps (called adenomas).
The study, presented on May 4, involves detecting serrated colorectal polyps. Unlike common adenomas, which usually protrude from the colon lining and are easy to see, serrated polyps are typically flat and the same color as the colon lining. Dr. Ahlquist says serrated polyps have been ignored or excluded from most screening studies to date because it wasnt clear they were associated with cancer. Now they are regarded as the forerunner in roughly 30 percent of colon cancers, says Dr. Ahlquist. Most of these are located on the right side of the colon, where screening has had less impact historically.
Detection of these important types of precancer by stool DNA testing offers promise in our efforts to more effectively and affordably prevent colorectal cancer , says Dr. Ahlquist. However, findings from both pilot studies need to be corroborated in larger studies.