Sporadic duodenal adenoma is associated with colorectal neoplasia

OBJECTIVE: The objective of this study was to assess the association between colorectal neoplasia and sporadic duodenal adenoma. METHODS: A retrospective case control study was conducted using the databases of two major teaching hospitals in Western Australia. The frequency of colorectal neoplasia in patients with sporadic duodenal adenomas was compared with that in a control group of patients presenting for endoscopies. The frequency of colorectal cancer in duodenal adenoma patients was also compared with the population incidence. RESULTS: Of 56 sporadic duodenal adenoma patients, 34 (61%) had been colonoscoped. When comparing the findings between patients with sporadic duodenal adenoma and an endoscoped control group, all colorectal neoplasias were significantly more common in the duodenal adenoma group (56% v 33%; odds ratio (OR) 2.4 (95% confidence intervals (CI) 1.1-5.4)). Although finding either advanced colorectal adenoma or cancer was also more common in duodenal adenoma patients (38% v 19%; OR 2.3 (95% CI 1.0-5.2)), as was finding colorectal cancer alone (21% v 8%; OR 3.0 (95% CI 1.0-9.1)), the results were not statistically significant. However, the incidence of colorectal cancer was much greater in duodenal adenoma patients than in the population (p<0.001). CONCLUSIONS: Sporadic duodenal adenoma has a clinically important association with colorectal neoplasia. Thus patients with duodenal adenomas should undergo colonoscopy to detect colorectal neoplasia.