Clinical outcomes of endoscopic resection for the treatment of gastric gastrointestinal stromal tumors originating from the muscularis propria: a 7-year experience from a large tertiary center in China.

BACKGROUND AND AIMS: Few studies have evaluated the value of endoscopic resection (ER) for the treatment of gastric gastrointestinal (GI) stromal tumors (GISTs) originating from the muscularis propria (MP) in a large population, and no studies have evaluated risk factors for piecemeal resection. This study aimed to evaluate the efficacy and safety of ER for gastric GISTs in a real-world setting and to explore factors associated with piecemeal resection. METHODS: From January 2013 to December 2019, 185 patients with gastric GISTs originating from the MP were assessed. Clinicopathological and endoscopic data were collected and analyzed. Baseline characteristics of the en bloc resection and piecemeal resection groups were compared to evaluate predictive factors for piecemeal resection. RESULTS: There were 71 males and 114 females with a mean age of 57.0 ± 9.7 years. The mean size of GISTs was 15 mm (range 4-65 mm). A total of 123 were very low risk, 52 were low risk, and ten were moderate risk. In this study, 103 GISTs were treated with endoscopic submucosal excavation (ESE), 68 GISTs were treated with endoscopic full-thickness resection (EFR), and 14 GISTs were treated with submucosal tunneling ER (STER). Either en bloc resection or complete resection was achieved in 160 (86.5%) patients. No recurrence was noted during follow-up. Only five patients experienced minor complications, with a complication rate of 2.7%. Multivariate analysis demonstrated that size (odds ratio [OR] 1.060, 95% confidence interval [CI] 1.004-1.118; P = 0.035) and shape (OR 5.434, 95% CI 1.638-18.027; P = 0.006) were independent predictors of piecemeal resection. CONCLUSION: ER was effective and safe for the treatment of gastric GISTs originating from the MP. Piecemeal resection did not seem to affect the efficacy of ER, and no recurrence was noted during follow-up. Large size and irregular shape are risk factors related to piecemeal resection of ER.