Risk Factors Of Ulcerative Colitis-associated Colorectal Cancer:a Single-Center Retrospective Study

ObjectiveTo analyze the incidence and risk factors of ulcerative colitis-associated coloretal cancer(UC-CRC) in222ulcerative colitis(UC) patients and provide the evidence for UC-CRC screening surveillance and prevention.Methods1. Two hundred and twenty-two dignosed as UC patients who admitted in Xiangya Hospital of Centeral South University from January2002to August2011were retrospectively evaluated, clinical characteristics and the incidence of UC-CRC were summarized.2.222cases were divided into UC-CRC group and UC group, the data of chinical characteristics, such as diarrhea, abdominal pain, anemia, weight loss, fever, hypoproteinemia and poylp of colon, and the common risk factors, such as extent and duration of UC, a family history of sporadic coloretal cancer, young age at colitis onset and backwash ileitis, were anlyzied by univariate and multivariate logistic regression, The relationship between the above factors and UC-CRC were analyzed.Results1. The most common symptoms were diarrhea (77.93%) and abdominal pain (76.58%), followed by mucus and pus-bloody stool (61.26%), anemia (41.44%), weight loss (41.44%), tenesmus (32.43%), hypoproteinemia(28.57%), abdominal distension (19.82%), fever (9.90%) and extraintestinal manifestations (6.76%) among the222patients. Two patients developed cancers (one with colon malignant lymphoma, and the other with well-moderately differentiated adenocarcinoma of the right semicolon), ten patients had precancerous lesions (nine with low-grade glandular epithelium dysplasia and one with medium-grade glandular epithelium dysplasia), The incidence of cancer and precancerosis in the UC patients was0.90%,4.50%, respectively. Another complications were the polyps in the colon(18.47%), intestinal obstruction(2.25%), toxic megacolon(1.35%), gastrointestinal hemorrhage(0.45%) and enterobrosis (0.45%).2. Sexes and average age between the two groups did not differ significantly (P>0.05). Univariate analysis showed a highly significant correlation between the polyps in the colon (OR5.000,95%CI:1.524to16.408; P=0.008) and with pancolitis (OR8.244,95%CI:2.367to28.710; P=0.001) and the risk of UC-CRC, no other factors reached statistical significance. On multivariate analysis, only with pancolitis remained significant (OR6.575,95%CI:1.826to23.699; P=0.010).Conclusions1. The incidence of cancer in the UC patients was0.90%, but much lower than that in western countries.2. The extent of UC is an important risk factor of UC-CRC, patients with pancolitis should received better surveillance programs.