Malignant Gastric Polyps - An Analysis of 7,284 Cases

Abstract

Purpose: Gastric polyps are encountered in up to 5% of upper endoscopies. Although there is consensus on the management of the majority of this heterogeneous group of lesions, no guidelines exist for malignant gastric polyps (MGP). While many MGP can be removed endoscopically, the risk of lymph node metastases remains. Aim: To define selection criteria for the endoscopic resection of MGP and to investigate factors influencing survival outcomes using a cancer registry. Methods: The Surveillance Epidemiology and End Result (SEER) database was used to identify patients diagnosed with MGP from 1998-2007. Multivariate logistic regression analysis was used to identify predictors of lymph node metastases and Cox regression analysis to identify adverse predictors of overall survival. Results: 7,284 patients were identified. 60% were men. The mean age was 71 years ± 0.1 and mean polyp size was 2.6 cm ± 0.4. The number of MGP increased from 2.2% in 1988 to 9.3% in 2007. The most frequent treatment was surgical resection (72%), followed by no surgery (17%), and endoscopic resection (10%). In patients undergoing surgical resection, high tumor grade, patient's age and tumor size predicted lymph node metastases (Table). For low grade MGP < 2 cm, only 4.9% had positive lymph nodes following surgery. Predictors of adverse survival included: size > 2 cm (HR 1.39, 95% CI 1.24-1.57), race other than Asian (White HR 1.48, 95% CI 1.32-1.66, Black HR 1.71, 95% CI 1.46-2.01), positive lymph nodes (N1 HR 1.57, 95% CI 1.38-1.79), and no resection (HR 4.22, 95% CI 3.58- 4.99) or endoscopic resection (HR 1.29, 95% CI 1.04- 1.62).Table: Predictors of lymph node metastasesConclusion: The optimal treatment for MGP remains surgical resection. However, for low grade, proximally located MGP < 2 cm, endoscopic resection may be adequate treatment due to the low risk of lymph node metastases. Assuming these selection criteria are confirmed by other studies, endoscopic resection is under-utilized in the management of MGP. This research was not supported by any industry grant.