DAVID T. RUBIN, MD: The risks of cancer in inflammatory bowel disease include more extensive disease -- in other words, more of the bowel being involved -- longer duration of disease, people who have a family history of colon cancer independent of a family history of inflammatory bowel disease are at increased risk for cancer with their IBD, and a condition which causes inflammation of the bile ducts in the liver called primary sclerosing cholangitis appears to be an independent risk factor for cancer in inflammatory bowel disease. More recently, researchers have suggested that the degree of inflammation is an independent risk factor for cancer.
ANNOUNCER: Colonoscopies and biopsies of tissue samples taken from the colon are the main techniques used in surveillance for colon cancer, or for pre-cancerous conditions.
DAVID T. RUBIN, MD: The sequence of events that lead to cancer in inflammatory bowel disease are not the same as cancer in people who don't have inflammatory bowel disease. What we believe to occur is that inflammation leads to a precancerous state called dysplasia.
Dysplasia is not necessarily visible to the colonoscopist, and so the way we look for this is by doing random surveillance biopsies throughout the bowel and then have a pathologist carefully analyze those for dysplasia.
ANNOUNCER: When the pathologist returns a report of dysplasia, many doctors recommend having the colon removed, regardless of how early or advanced are the cellular changes.