[The pathogenesis of ulcerative colitis-associated colorectal cancer]

The fact that there is an increase in cases of ulcerative colitis-associated dysplasia and colitic cancer raises some problems for clinical practice and pathological diagnosis. How to detect ulcerative colitis-associated dysplasia and early cancer endoscopically? How to discriminate inflammatory regenerative epithelium from UC-associated dysplasia and aberrant crypt foci histologically? How to distinguish dysplasia-associated lesion or mass from sporadic adenoma pathologically? UCAC has established risk factors including, among others, long duration of disease, large extent and low activity of disease, and the lack of adequate surveillance and therapy. Colonoscopic and histological evidence of low grade and high grade dysplasia means the possible evidence of coexisting carcinoma. Carcinoma typically may occur in the entire colon, is often multiple and has undifferentiated histology. Important factor is the effectiveness of dysplasia surveillance as a population based strategy to decrease colorectal cancer mortality in inflammatory bowel disease patients. Colitis-related cancer may have distinct pathogenesis to sporadic colorectal cancer.