Backwash ileitis is strongly associated with colorectal carcinoma in ulcerative colitis

Background & Aims: Commonly accepted risk factors for colorectal carcinoma (CRC) in ulcerative colitis are duration and extent of disease, By identify ing still unknown risk factors, surveillance strategies may be improved fur ther. We investigated whether backwash ileitis is also a factor associated with CRC in ulcerative colitis. Methods: Five hundred ninety consecutive pa tients with ulcerative colitis who received restorative proctocolectomy wer e classified into 3 groups: (1) pancolitis with backwash ileitis, (2) panco litis without backwash ileitis, and (3) left-sided colitis. The association with CRC was analyzed in these 3 groups of patients. As further risk facto rs, we investigated disease duration, dysplasia, primary sclerosing cholang itis, age at diagnosis of disease, disease activity, and gender. Univariate and multivariate logistic regression were used for analysis. Results: CRC was diagnosed in 11.2% of all patients. CRC was found in 29.0% of 107 patie nts in group 1, compared with 9.0% of 369 patients in group 2, and in 1.8% of 114 patients in group 3 (P < 0.001). Cancer patients in group 1 showed s ignificantly move multiple tumor growth (45.2%) than patients in group 2 (2 4.2%) and group 3 (0%) (P = 0.041). Estimating the relative risk for CRC in the multivariate analysis, patients in group 1 showed a significantly high er odds ratio than patients in groups 2 and 3 (odds ratio: 19.36 vs. 9.58 v s. 1; P < 0.001). High-grade dysplasia, low-grade dysplasia, disease durati on of more than 10 years, and disease duration of less than 10 years in pat ients older than 45 years were further factors with significantly increased risk (odds ratios: 21.69, 6.36, 3.63, 4.37), but primary sclerosing cholan gitis was not (P = 0.080). However, primary sclerosing cholangitis was stro ngly associated with backwash ileitis. Conclusions: There is a strong assoc iation of backwash ileitis with CRC in patients with ulcerative colitis who undergo proctocolectomy. The predictive value of backwash ileitis for CRC and premalignant dysplasia in patients with ulcerative colitis should be in vestigated in future studies based on colonoscopic surveillance.