Sporadic duodenal adenoma and the association with colorectal neoplasia: a case-control study

Sporadic duodenal adenomas are an uncommon finding. It is not clear whether patients with sporadic duodenal adenoma have a greater risk for colorectal neoplasia and should undergo colonoscopy. The aims of the present study were to estimate the prevalence of colorectal neoplasia in patients with sporadic duodenal adenoma, and to compare colorectal neoplasia rates in patients with sporadic duodenal adenomas versus those without them.

A retrospective case-control study was conducted to identify sporadic duodenal adenoma patients using the databases of two academic and one regional hospital in the Netherlands. Colonoscopic findings in the sporadic duodenal adenoma patients were compared with those of a control group of patients who underwent both gastroduodenoscopy and colonoscopy. Furthermore, the frequency of colorectal cancer in the sporadic duodenal adenoma patients was compared with the population incidence of colorectal cancer.

During the period 1991-2006, 102 patients in total with sporadic duodenal adenomas were identified. Colonoscopy was performed in 49 patients (48%), and colorectal neoplasia was present in 21 of these patients (43%). There was a significantly higher rate of both colorectal neoplasia (43%vs 17%, odds ratio [OR] 3.6, 95% confidence interval [CI] 1.7-7.4) and advanced colorectal adenoma (18%vs 3%, OR 7.8, 95% CI 2.1-29.4) in the patients with sporadic duodenal adenoma compared to that in the control group. Also, the incidence of colorectal cancer was higher in sporadic duodenal adenoma patients compared to that in the population (P= 0.02).

Individuals with sporadic duodenal adenomas appear to be at a significantly higher risk of colorectal neoplasia, and therefore should undergo colonoscopy.