Endoscopic and pathological features of neoplastic transformation of gastric hyperplastic polyps: Retrospective study of 4010 cases.

Background: Hyperplastic polyps, which represent 30%-93% of all gastric epithelial polyps, are the second most common type of gastric polyps after fundic gland polyps. They were previously considered to have no risk of neoplastic transformation. Recently, an increasing number of cases of gastric hyperplastic polyps (GHPs) combined with neoplastic changes have been reported; however, the specific mechanism underlying their transformation has not been thoroughly explored.

Aim: To investigate the clinical, endoscopic, and pathological characteristics of the neoplastic transformation of GHPs and explore the risk factors.

Methods: A retrospective analysis was performed on 4010 cases of GHPs diagnosed by gastroscopy and pathological examination at the hospital from 2005 to 2021. In total, 3874, 119, and 17 cases were in the group without intraepithelial neoplasia (IN), with low-grade IN, and with high-grade IN, respectively. The data analysis examined the association of endoscopic and pathological features with risk factors for neoplastic transformation. Factors with significant differences were entered into univariate logistic regression, followed by multivariate logistic regression analysis.

Results: Univariate analysis revealed diameter, multiple polyp presence, redness, rough surface, lobulation, erosion, Yamada classification, location, and gastric mucosa were risk factors for neoplastic transformation. Multivariate analysis showed that age > 65 years [odds ratio (OR) = 1.789; 95% confidence interval (CI): 1.227-2.609; = 0.003], male sex (OR = 1.680; 95%CI: 1.158-2.438; = 0.006), multiple polyps (OR = 1.851; 95%CI: 1.230-2.784; = 0.003), pedunculated or semi-pedunculated shape (OR = 2.722; 95%CI: 1.689-4.388; < 0.001), and polyp diameter were significantly associated with GHPs that demonstrated neoplastic transformation. Compared with chronic superficial gastritis, autoimmune gastritis, atrophic gastritis, and gastritis with IN were independent risk factors for neoplastic transformation [(OR = 2.672; 95%CI: 1.559-4.579; < 0.001), (OR = 1.876; 95%CI: 1.134-3.103; = 0.014), and (OR = 5.299; 95%CI: 3.173-8.849; < 0.001), respectively].

Conclusion: Male sex, age > 65 years, multiple polyps, pedunculated or semi-pedunculated shape, polyp size > 1 cm, and specific background gastric mucosa are key indicators for predicting neoplastic transformation of GHPs.