Duodenal involvement in MUTYH-associated polyposis: findings from an international study and implications for endoscopic surveillance.

Abstract

Objectives: This study aimed to better document incidence and progression of duodenal disease in MUTYH -associated polyposis (MAP). Methods: Incidences of duodenal cancer, and duodenal polyposis by age and genotype were assessed in individuals with genetically confirmed MAP. Results: At first endoscopy, 91/679 participants (13.4%) had duodenal adenoma(s) at a median age of 53 years (range 22 to 81 years). 439/679 participants had 1370 further endoscopies, over a median period of 6.3 years (range 1 month to 30 years). This included 365 without adenomas at first endoscopy, of whom 83 (22.7%) developed non-ampullary adenomas during follow-up at a median age of 53 years (range 29-76). Thirty-eight adenomas (5.5%) contained high-grade dysplasia (HGD), of which thirty-five had a known size and 20 (57.1%) of these were 10mm or smaller. Ampullary lesions were uncommon (31/679, 4.6%). Duodenal cancer was diagnosed in 5/679 participants (0.74%) at a median age of 65 years (range 47-83 years) and at a median of 12 months (range 9-24 months) following a surveillance endoscopy. At least four were located distally (in the third or fourth part). The cumulative incidences of duodenal adenomas and cancer at 70 years were 16.5-63.5%, depending on genotype, and 0.58%, respectively. Adenoma incidence was significantly higher in Y179C (hazard ratio 5.33 (2.94–9.67, <0.001) and E480X (4.07 (2.16–7.67), <0.001) than G396D homozygotes. Conclusions: Future clinical guidelines for MAP should consider genotype-specific recommendations for duodenal surveillance, the importance of assessing the distal duodenum (i.e. D3, D4) and polypectomy of all detectable adenomas.

The authors' abstract, as published at the source. The American Journal of Gastroenterology, 2026 · DOI ↗