Abstract
BACKGROUND: Gastric gastrointestinal stromal tumors (gGISTs) are the most prevalent type of GISTs, particularly affecting elderly patients. Nevertheless, population-based research on the clinical characteristics and prognosis of gGISTs in this age group remains unreported. The aim of this study is to fill this gap by conducting a comprehensive population-based analysis of the clinical features and prognostic outcomes of elderly patients diagnosed with gGISTs in the United States. METHODS: Utilizing the Surveillance, Epidemiology, and End Results (SEER) database, all patients diagnosed with gGISTs between 2010 and 2019 were identified. Multiple imputation (MI) was used to address missing data, and propensity score matching (PSM) was applied to reduce selection bias. To evaluate overall survival (OS) and cancer-specific survival (CSS), we assessed the impact of demographic and clinical factors using Cox proportional hazards models and Kaplan-Meier analyses. RESULTS: The study cohort included 4,551 patients in total, comprising 2,423 elderly individuals (≥65 years) and 2,128 non-elderly individuals (<65 years). Multivariate Cox regression analysis revealed that, among elderly patients, race, sex, metastasis (M) stage, mitotic rate, surgery, and marital status were independent risk factors for OS, while M stage, surgery, mitotic rate, chemotherapy, and marital status were associated with CSS. Even after PSM, OS and CSS outcomes for the elderly group remained significantly poorer (P<0.05). The mean 1-, 3-, and 5-year OS rates in elderly patients were 90.0%, 77.0%, and 59.0%, respectively, with corresponding CSS rates of 95.7%, 89.0%, and 78.3%. Compared to the non-elderly group, the elderly group exhibited significantly worse OS [hazard ratio (HR) 2.37, 95% confidence interval (CI): 2.06-2.73, P<0.001] and CSS (HR 1.47, 95% CI: 1.21-1.79, P<0.001). In addition, they had a higher proportion of Caucasian patients, underwent surgery and chemotherapy less frequently, and had a significantly lower rate of lymph node metastasis (P<0.05). CONCLUSIONS: Although surgical intervention may improve the prognosis of elderly patients with gGISTs, this population-based study found that they exhibit distinct clinical characteristics and have a poorer overall prognosis.