Detection of Colorectal Precancerous Lesions in Inflammatory Bowel Disease

Research teams led by Mayo Clinic have demonstrated that stool DNA testing may be useful for detection of premalignant dysplasia in patients with inflammatory bowel disease (IBD). 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 3 at Digestive Disease Week, involves identifying both cancer and a precancerous lesion, called dysplasia, in people who suffer from IBD. In a blinded study with 10 cases and 10 controls done in conjunction with Mount Sinai Medical Center and the University of Chicago, researchers found that stool DNA testing was positive in nine out of 10 cases (five of five with cancer, and four of five with dysplasia).
This study shows that cancer and pre-cancer in IBD can be detected noninvasively, says Dr. Ahlquist. The 90 percent detection rate by stool DNA testing is remarkable. Its important for people with IBD because they are at much higher risk for colorectal cancer than the general population. Given the limitations of colonoscopies in detecting these lesions, stool DNA testing could play a complementary role to improve the effectiveness of cancer surveillance.