Colorectal tumor comorbidity is common in patients with duodenal tumors: Exploratory cross-sectional study.

Background and study aims The duodenum and colorectum are target organs for familial colorectal adenomatous polyposis, however, the association of duodenal epithelial tumors (DETs) and colorectal tumors is still controversial. The aim of our study was to elucidate the association between DET and colorectal tumor. Patients and methods This was an exploratory cross-sectional study of patients with DETs treated by endoscopic resection at our hospital, between November 2018 and October 2022. Individuals who underwent colonoscopy as part of the health screening comprised the reference control group for comparison. In both groups, lesions suspected of being tumors were resected. The main outcome was the adenoma detection rate (ADR). Other outcomes were the detection rate for advanced neoplasia (AN) and risk factors for colorectal adenoma and AN, evaluated using univariate and multivariable analyses. Results Analyses were based on data from 163 individuals in the DET group and 177 in the control group. ADR was higher in the DET (63.2%) than in the control (23.6%) group ( P < 0.001). AN and invasive cancer rates were also significantly higher in the DET than in the control group (AN: 20.9% vs 3.4%, respectively, P < 0.001; invasive cancer: 3.1% vs 0%, respectively, P < 0.001). On logistic regression analysis, DET was found to be associated with a 5-fold increase in the detection rate of adenoma and 6-fold increase in AN detection. Conclusions The study revealed significant association between DET and high ADR and a higher frequency of AN and invasive cancer. Screening colonoscopy is suggested for patients with DETs.