Suggested cutoff tumor size for management of small EUS-suspected gastric gastrointestinal stromal tumors

Background/Purpose Although the incidence of asymptomatic small gastric submucosal tumors increased gradually with routine medical health examination, there was little clinical evidence for management consensus in these small gastric submucosal tumors including endoscopic ultrasound (EUS)-suspected gastric gastrointestinal stromal tumors (GISTs). We investigated the clinical course of small EUS-suspected gastric GISTs and propose a cutoff value of tumor size for treatment policy. Methods In this retrospective study, 50 patients with EUS-suspected gastric GISTs of sizes less than 3 cm were enrolled and were followed up by EUS at least twice over a period of more than 24 months (range 24–101 months). An at least 20% increase of the maximal diameter of the tumors was set as a significant change. Results Significant changes in tumor size were found during the follow-up in 14 patients (28.0%). The one-dimensional 20% change corresponded well to 50% change in two-dimensional area measurement (correlation coefficient = 0.929). The receiver operating characteristic curve analysis showed that the best cutoff size, associated with tumor progression, was 1.4 cm having an 85.7% sensitivity, 86.1% specificity, and 86.0% accuracy. A larger tumor size (35.7% vs. 2.8%, p = 0.005) and irregular tumor margin on the EUS (71.4% vs. 0, p = 0.004) were two significant factors associated with the progression of tumor growth of small suspected gastric GISTs. Conclusion Small EUS-suspected GISTs, larger than 1.4 cm, with irregular margin were associated with significant progression. This subgroup is suggested to be monitored by more intensive follow-up.