溃疡性结肠炎和克隆病的结肠癌发生率增高 ,尤以前者 ,定期结肠镜随访 ,活检标本显示发育不良 ,即列为癌肿的早期指标 ,需作结肠切除。溃疡性结肠炎的附表　各基因型的出现率 ( % )基因型 UC伴发育不良UC不伴发育不良结　肠直肠癌 对照组AB 0 4 0 2AC 0 0 0 3AD 0 0 4 0BB 5417 Ulcerative colitis and Crohn’s disease colon cancer increased, especially in the former, regular colonoscopy follow-up, biopsy specimens showed dysplasia, which is listed as an early indicator of cancer, need for colonic resection. Incidence of ulcerative colitis Incidence of each genotype (%) Genotype UC with dysplasia UC without hypoplastic colorectal cancer control group AB 0 4 0 2AC 0 0 0 3AD 0 0 4 0BB 5417