Colorectal Cancer: Ulcerative Colitis-Associated Neoplasia

The incidence of colorectal neoplasia is increased in patients with long-standing and extensive ulcerative colitis (UC), and death from colorectal neoplasia is the most important factor for long-term mortality in patients with UC. To improve the prognosis of patients with UC-associated neoplasia, it is very important to diagnose it at an early or precancerous state in patients with long-standing UC. However, UC-associated neoplasia is often difficult to detect endoscopically and difficult to discriminate from inflammatory regenerative epithelium pathologically. There are three important problems in diagnosing UC-associated neoplasia: the first is how to detect UC-associated dysplasia and early cancer endoscopically; the second is how to discriminate UC-associated dysplasia from inflammatory regenerative epithelium pathologically; and the third is how to identify individuals at increased risk of neoplasia, especially dysplasia, in patients with long-standing and extensive UC. We reviewed the clinicopathological and genetic characteristics of UC-associated neoplasia focusing on these three problems.