Frequency and risk factors for malignant evolution of gastric hyperplastic polyps in a country with intermediate-high risk for gastric cancer

Abstract

Background and Aims: Gastric hyperplastic polyps (GHPs) carry a neoplastic transformation risk of up to 5%, with previous studies indicating an increased risk with larger polyp size. We aimed to evaluate the frequency and risk factors of its malignant transformation in a Portuguese cohort. Methods: A multicentric retrospective cohort study was conducted including all patients undergoing endoscopic resection of GHPs ≥10mm from January 2013 to December 2024 in Portuguese tertiary reference centers. Patients with hereditary polyposis syndromes were excluded. Demographic, clinical, endoscopic, and histopathological data were collected. Results: A total of 782 GHPs from eight centers were evaluated. Evidence of advanced gastritis stage (OLGIM≥3) and synchronous gastric neoplasia was present in 57 (10.2%) and 37 (4.7%) cases, respectively. Most GHPs were removed by endoscopic mucosal resection (86.6%); Neoplastic transformation was observed in 33 polyps (4.2%) - 25 (3.2%) low/high-grade dysplasia and 8 (1.0%) adenocarcinomas; the resection was non-curative in 30.3% of cases. In the multivariate analysis, OLGIM≥3 (OR 4.994, 95%CI 1.036-24.065), lesion size ≥25 mm (OR 7.973, 95%CI 7.973 (1.242-51.180), flat/depressed morphology (OR 9.57, 95%CI 1.096-83.712) and synchronous gastric neoplasia (OR 16.956, 95%CI 2.737-105.045) were independently associated with a higher risk of neoplastic transformation. Conclusions: The risk of malignant transformation of GHPs is non-negligible, with lesion size, morphology and concomitant precancerous gastric conditions/lesions being associated with a higher risk. Nevertheless, the rate of non-curative endoscopic resection is high. The identification of these features may contribute to optimizing endoscopic resection techniques and surveillance strategies in high-risk patients.