Long-term prognosis and risk factor-based surveillance strategy for patients with small gastric subepithelial lesion using endoscopic ultrasonography

Background and Objectives: Initial surveillance strategy and subsequent monitoring for small gastric subepithelial lesions (SELs) lack a consensus. This study aimed to investigate the risk factors and performance of predictive markers for lesions requiring surgical intervention in patients with small gastric SELs. Methods: We retrospectively reviewed data of patients who underwent EUS at least twice between 2010 and 2023. Group S1 was defined as patients with a ≥20% increase in size from the initial EUS. The S1 was further divided into 2 groups according to requiring surgical intervention (S2 and S3). Results: Of the 476 patients, 106 (22.2%) had increase in size by ≥20% compared with the initial EUS (S1). The mean follow-up duration in the S1 was 70.2 months. Seven (1.5%) and 38 (8.0%) lesions were observed to have increased in size and were confirmed as gastrointestinal stromal tumors, respectively (S2). Lesions in the lesser curvature (odds ratio [OR]: 6.0, 95% confidence interval [CI]: 2.087–17.148, P < 0.001) and size of ≥12.8 mm (OR: 4.2, 95% CI: 2.083–8.542, P < 0.001) were risk factors for S2. Lesion size ≥12.8 mm is a key risk factor requiring timely intervention based on the Kaplan–Meier analysis. An increasing rate (0.7 mm/yr) showed superior performance as a predictive risk factor for S2 than having a lesion size ≥12.8 mm (area under the receiver-operating characteristic curve: 0.887 vs. 0.734, P < 0.001). Conclusions: Although the size of the SELs increased, the classification for group S2 was very important. These results emphasize the necessity for effective follow-up strategies, including timely interventions, for small gastric SELs.