[Malignant transformation in ulcerative colitis and surgical implications]

Patients with ulcerative colitis (UC) are at higher risk for cancer. Risk factors are duration of disease, extent of colitis, associated primary sclerosing cholangitis and possibly early onset of UC in childhood. Epithelial dysplasias are considered as precursors of colorectal cancer within the concept of an inflammation-dysplasia-carcinoma sequence. Dysplasia originates multifocally and is difficult to identify by colonoscopy. Histomorphological diagnosis can also be problematical. Surveillance programs utilize colonoscopy with random biopsies to diagnose dysplasia in patients with risk factors. The efficiency of these programs can be markedly increased when certain rules are applied. The ultimate aim must be to perform a proctocolectomy in patients at higher risk before invasive cancer develops. With only a few exceptions, colorectal cancer in UC can be treated by restorative proctocolectomy. Partial resection of the colon should be avoided because of the high frequency of occult carcinomas and multifocal carcinogenesis. There are first results that indicate a higher risk for malignant deterioration in the terminal ileum. After an ileoanal pouch procedure patients with chronic pouchitis seem to have a higher risk for dysplasia. At the moment the risk for malignancy cannot be calculated because of the relatively short follow-up time after ileoanal pouch procedures. However, it is recommended that after restorative proctocolectomy patients be followed by endoscopy and random biopsies for the rest of their lives.