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

Sporadic duodenal adenomas are uncommon. Prior studies show that patients with sporadic duodenal adenoma have increased risk of colorectal neoplasia and should undergo colorectal screening. However, the nature of the risk, location, and type of colorectal neoplasia are not well studied. We aimed to identify the risk of colorectal neoplasia in patients who have duodenal adenomas. A retrospective case-control study was conducted to identify sporadic duodenal adenoma patients using the databases at one academic center. Colonoscopic findings including histology and location of colorectal cancer neoplasia in sporadic duodenal adenoma patients were compared with a control group of patients without duodenal adenomas who underwent both gastroduodenoscopy and colonoscopy. Hundred and two patients with sporadic duodenal adenomas or adenocarcinomas were identified. Colonoscopy was performed in 47 patients (46%), and colorectal neoplasia was present in 22 (46%). There was a significantly higher rate of colorectal neoplasia in patients with sporadic duodenal adenoma (43%) compared to the control group (24%) odds ratio 4.8, 95% confidence interval (1.7-7.4), but not for advanced colorectal adenoma (9 vs. 26%, p = 0.17). Case patients had significantly more right-sided lesions than matched controls (p = 0.02). Single-center, retrospective study. Individuals with sporadic duodenal adenomas have a significantly higher risk of colorectal neoplasia and proximal location of neoplasia. Therefore, these patients should undergo colonoscopy with particular attention to the right colon.