Large proximal gastric GIST tumours: downsizing by imatinib and subsequent endoresection

Abstract

Surgical removal is recommended for gastrointestinal stromal tumours (GISTs) larger than 3 cm due to their potential for malignancy but limited wedge resection is not possible in the proximal stomach. Endoscopic removal of larger lesions has been technically limited in complex anatomical regions such as cardia. We report two cases of large proximal (cardia/fundus) GIST tumours (51 and 60 mm) which were downsized (to 26 and 36 mm) by 3–7 months of imatinib therapy followed by transmural endoscopic resection. Follow-up of 23 and 16 months including endoscopy and CT was unremarkable. GISTs commonly occur in the stomach.1 2 Due to their malignant potential, surgery is generally recommended.3–5 Recently, endoscopic resection of submucosal tumours (SMTs) has made significant progress.6 The European Society of Gastrointestinal Endoscopy recommended endoscopic resection for gastric GISTs<35 mm projecting into the lumen.3 Endoscopic full-thickness resection (EFTR), an extension of submucosal dissection, has shown promising results for SMTs arising from the deep muscularis propria (MP), particularly in the gastric fundus.7 However, achieving R0 resection in GISTs>35 mm remains challenging.8 Large GISTs in anatomically complex areas such as the cardia and fundus may still necessitate surgical resection.2 Radical surgery, however, poses risks to cardia function and patient quality of life.9 Preoperative imatinib can shrink tumours, reduce mitotic activity and lower recurrence risk.9 10 The American College of Gastroenterology guidelines suggested neoadjuvant imatinib to facilitate tumour reduction in large GISTs, enhancing the feasibility of minimally invasive endoscopic resection. Hence, in this context, we explored the combination of preoperative imatinib with EFTR as a novel, minimally invasive strategy for treating large gastric GISTs. Our primary outcomes suggested this approach may be a viable alternative for GISTs in gastric anatomical complex regions. Case 1 was a 65-year-old woman with abdominal distension and belching for several months. Gastroscopy revealed …