Nationwide Multicenter Study of Advanced Endoscopic Resection and Malignant Risk Model for Gastric Myogenic Tumors (GASTRO Trial)

Abstract

Background/Objectives: The prevalence of gastric subepithelial lesions (SELs) is rising. Endoscopic resection (ER) technique provides a minimally invasive alternative to manage gastric SELs. This study aims to evaluate the effectiveness and safety of ER for gastric myogenic tumors, and examine predictors for gastrointestinal stromal tumors (GISTs). Methods: The retrospective study was conducted between 2012 and 2024 at nine tertiary centers in Taiwan. We enrolled patients with endoscopic ultrasound (EUS)-documented gastric myogenic tumors managed by endoscopic muscular dissection (EMD), endoscopic subserosal dissection (ESSD), submucosal tunneling endoscopic resection (STER), and endoscopic full-thickness resection (EFTR). Clinical manifestation, endoscopic features, and outcomes were analyzed. Results: We enrolled 325 patients with 332 lesions [mean EUS size 14.5 mm, 153 (46.1%) leiomyoma, 152 (45.8%) GISTs, 27 (8.1%) other histology]. ER techniques were 193 (58.1%) EMD, 46 (13.9%) ESSD, 28 (8.4%) STER, and 65 (19.6%) EFTR. Technical success, en bloc, and R0 resection rates were 97.0%, 94.3%, and 88.9%, respectively. Twenty-four (9.0%) procedures were shifted to unintentional EFTR, and 21 (6.3%) patients had complications. No recurrence occurred during mean follow-up period of 921.4 days. Two (0.6%) patients died of non-procedure related reasons. Old age, fundus location, heterogeneous echotexture, and exophytic growth pattern were independent risk factors for GIST (all with p < 0.05). Using the above factors, we built a prediction model with sensitivity of 77.0%, specificity of 85.6%, and AUC of 0.8771. Conclusions: ER is an efficient and safe management for gastric myogenic tumors. The histological type could be predicted by demographic characteristics and EUS features.

Keywords: EUS; GIST; endoscopic resection; myogenic tumor; subepithelial lesion.

Figure A1

Distribution of EUS size, echotexture, and growth feature with histology. The larger size of the tumors is represented by the farther distance of the dots from the origin. EUS, endoscopic ultrasound; GIST, gastrointestinal stromal tumor.

Figure A2

The ROC curve of age for prediction of GIST, AUC 0.7329. ROC, receiver-operation characteristic; GIST, gastrointestinal stromal tumor; AUC, area under the curve.

Figure A3

The ROC curves of tumor size for prediction of GIST. (a) ROC curve of EUS tumor size. AUC 0.6471. (b) ROC curve of endoscopic tumor size. AUC 0.5444. ROC, receiver-operation characteristic; EUS, endoscopic ultrasound; GIST, gastrointestinal stromal tumor; AUC, area under the curve.

Figure 1

Different endoscopic resection techniques for gastric myogenic tumor. In the figures, we showed the appearance of the lesions before the procedures, during dissection, after closure, and when the lesions were retrieved. (Left Column) ESSD. (Middle Column) Exposed EFTR. (Right Column) Non-exposed EFTR with Padlock clip. ESSD, endoscopic subserosal dissection; EFTR, endoscopic full-thickness resection.

Figure 2

Flowchart of enrollment. EUS, endoscopic ultrasound.

Figure 3

Size distribution of GISTs according to the risk stratification. GIST, gastrointestinal stromal tumor.

Figure 4

Prediction model for GIST, and the ROC curve of the prediction model with AUC 0.8771. ROC, receiver-operation characteristic; GIST, gastrointestinal stromal tumor; AUC, area under the curve.