ENDOSCOPIC SCREENING FOR DYSPLASIA AND MUCOSAL ANEUPLOIDY IN ADOLESCENTS AND YOUNG-ADULTS WITH CHILDHOOD-ONSET COLITIS

Objectives: In adults, the premalignant nature of ulcerative colitis ( UC) has long been accepted. Currently there is increasing concern that Crohn's disease (CD) may be equally premalignant. As a consequence, m ost adults with long-standing UC and many with chronic CD are enrolled in ongoing endoscopic cancer surveillance programs. In contrast, the risk of colonic cancer in adolescents and young adults with either for m of colitis is less well recognized, and the need for dysplasia and c ancer screening in this population has not been systematically evaluat ed. We therefore report the prospective results of colonoscopic cancer screening in such a young population. Methods: Thirty-five adolescent s and young adults with long-standing colitis (18 UC, 17 CD; 21 +/- 3 yr old, 11 +/- 3 yr colitis duration) underwent colonoscopic cancer sc reening. All had multiple biopsies for flow cytometry and light micros copy. Results: Seven subjects had aneuploidy (3/18 UC, 4/17 CD). Of th ese seven, only two had dysplasia [one high grade (UC), one low grade (CD)]. One additional subject had indefinite dysplasia with normal flo w cytometry. The remaining 27 subjects had both normal flow cytometry and light microscopy. Five of the seven aneuploid subjects underwent s urgery within 1 yr of screening. Four, including both subjects with dy splasia, had no evidence of colon cancer at surgery. However, a 24-yr- old female with a 14-yr history of UC and no evidence of dysplasia or cancer at screening had a Dukes C adenocarcinoma. Conclusions: Adolesc ents and young adults with childhood onset UC or CD are at risk for an euploidy, dysplasia, and colon cancer. Aneuploidy can be evident 10 yr after the onset of colitis and in patients as young as 16 yr of age. Therefore, the risk for colon cancer in patients with childhood onset colitis must be based on the duration of the illness, not on their chr onological age. Incorporation of flow cytometry into an endoscopic scr eening protocol appears to enhance the ability to identify individuals at highest risk for colon cancer.