Frequency and Features of Duodenal Adenomas in Patients With MUTYH-Associated Polyposis

MUTYH-associated polyposis (MAP) is similar to familial adenomatous polyposis (FAP), in that it increases the risk for duodenal adenomas and cancer. Almost all patients with FAP develop duodenal adenomas and 5% develop duodenal cancer. Little is known about the prevalence of duodenal adenomas and cancer in patients with MAP, but current surveillance recommendations are the same for patients with FAP-they should begin surveillance when they are 25 years old. We aimed to assess the prevalence, extent, and progression of duodenal adenomas in patients with MAP and evaluate upper gastrointestinal tract surveillance recommendations.

In a retrospective study, we collected data on all patients (n = 92) with MAP undergoing surveillance esophagogastroduodenoscopy from registries at St Mark's Hospital (London, UK) and the Academic Medical Center (Amsterdam, The Netherlands) from 2002 through 2014. We collected information on adenoma development, age at adenoma detection, interventions, and disease progression.

Duodenal adenomas were detected in 31 patients (34%), at a median age of 50 years. When duodenal polyposis first was detected, it was Spigelman stages I or II in 84% of patients; most had few small polyps, without high-grade dysplasia or villous features. Subsequent esophagogastroduodenoscopy evaluation of 18 of these patients found that 14 (78%) had Spigelman stages 0 to II disease (median follow-up period, 7.8 y). Disease progressed in stage in 6 patients, over 9.5 years, because of lesion size or villous features (2 reached stage IV disease). Adenomas were down-staged in 8 patients after biopsy or polypectomy analyses, and were unchanged for 3 patients.

In a data analysis from 92 patients with MAP, duodenal polyposis seemed to develop less frequently than in patients with FAP, and developed at a later age. Increasing lesion size and villous change appear to promote adenoma progression, rather than polyp number or dysplasia. It may be time to consider a new staging system for patients with MAP, to better determine disease severity and surveillance strategies.