Factors Affecting Recurrence-free Survival in Gastric Gastrointestinal Stromal Tumors: A Single Center Experience

Aim: Gastrointestinal stromal tumors (GISTs) are extremely rare. In this study, we aimed to analyze the factors affecting disease-free survival (DFS) in patients operated for non-metastatic gastric GIST (gGIST). Methods: This was a retrospective analysis of 34 patients with resectable gGIST who were followed up and treated at the oncology clinic between 2008 and 2019. Patients with metastatic disease and non-gastric disease and those aged <18 years were excluded. Results: Seventeen (50%) patients were male. The median age was 64 years. According to Miettinen Risk Scores, seven patients were (20.6%) in very low-risk group, five (14.7%) in low-risk group, 17 (50%) in moderate-risk group, and five (14.7%) patients were in high-risk group. Adjuvant therapy was given in 11 (32.4%) patients. The 5- and 10-year DFS rates were same as 79.2%. The 5- and 10-year overall survival rates were 90.9% and 85.6%, respectively. In multivariate analysis, presence of necrosis [Hazard rate (HR)=9.5], being in high-risk group (HR=27.2), Ki-67 (HR=1.03), and receiving adjuvant therapy (HR=0.51) were factors affecting DFS. Conclusion: We assume that adjuvant therapy should be given in high-risk patients operated for gGIST in the presence of necrosis and high Ki-67.