WESTPORT, May 15 (Reuters Health) - A microsatellite marker for IBD1, a gene that has been associated with Crohn's disease and ulcerative colitis, may identify patients with ulcerative colitis who are likely to develop dysplasia and who may thereby be at increased risk for colorectal cancer.
Dr. Susan Galandiuk from the University of Louisville, in Kentucky, and a multicenter group extracted DNA from peripheral leukocytes of 152 patients. Twenty-two of the subjects had ulcerative colitis and dysplasia, 48 had ulcerative colitis without dysplasia and 24 had colorectal cancer. In addition the researchers studied 58 patients with noninflammatory bowel disease, nonmalignant gastrointestinal tract disease.
They amplified D16S541, a microsatellite marker for IBD1, by polymerase chain reaction and used autoradiography to identify the genotypes. Dr. Galandiuk's group was able to identify 6 alleles and 15 genotypes for D16S541.
The researchers found that 33% of the patients with cancer, but only 12% of controls, had genotype CC. Of the patients with ulcerative colitis and dysplasia, 32% had genotype CC compared with 8% of the patients who had ulcerative colitis without dysplasia.
Dr. Galandiuk and colleagues write in the May issue of Archives of Surgery, "We believe that a panel of molecular markers, of which D16S541 would be only one, could potentially be used as an adjunct to current screening protocols to identify patients at increased risk of developing colorectal cancer."
The group points out three benefits of such screening. First, these markers could be used to assess cancer risk independently of disease duration. Second, assessment could be done at any stage of the disease. And third, the use of the markers would "allow for less-intensive screening of patients who are not deemed to be at high risk of developing colorectal cancer."
Arch Surg 2000;135:582-585.
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