Deciphering the Clinical Spectrum of Gastric Disease in Patients with Juvenile Polyposis Syndrome

Background and aimsJuvenile Polyposis Syndrome (JPS) is a rare hereditary autosomal dominant cancer-predisposition syndrome caused by germline pathogenic variants (PV) located in SMAD4 or BMPR1A genes. Precise clinical and endoscopic presentation as the evolution of gastric lesions remain ill-known.MethodsClinical, endoscopic, genetic, pathological data from patients with SMAD4 or BMPR1A PVs included between 2007 and 2020 in the French network on rare digestive polyposis (RENAPOL) database were prospectively collected to address uncertainties regarding gastric involvement.ResultsThirty-six patients were included: 25 (69.5%) had SMAD4 PVs, 11 had BMPR1A PVs. For SMAD4 PV carriers, median age at inclusion was 43.0 years [range 10-78]. At baseline esophagogastroduodenoscopy (EGD), 22/25 (88%) exhibited at least one gastric juvenile polyp, 5/25 (20%) had macroscopic signs of inflammatory gastritis. Early gastric disease was mostly located under the cardia, then progressed to gastric antrum and body. During a mean follow-up period of 55.0 months, 12/25 had gastric disease progression (i.e. new juvenile polyps (91.6%), diffuse gastric involvement (41.6%), inflammatory flat progression (25%)). Among 62 biopsies, low-grade dysplasia was observed in 5 (7.5%) samples from 2 patients. Nine carriers (36%) underwent gastrectomy (mean age of 47.2 years) due to diffuse gastric involvement or worsening clinical symptoms. Gastric adenocarcinoma (T1) was found in one gastrectomy specimen. Among the 11 patients with BMPR1A PVs, 2 had gastric hamartomatomas at baseline EGD, none with dysplasia or symptoms.ConclusionGastric involvement in JPS appears to be progressive during life, initiating in the cardia area, and mostly concerns SMAD4 PV carriers.