Regional Variability in Curative-Intent Surgical Treatment Among Medicare Beneficiaries With Potentially Curable Gastric Cancer

INTRODUCTION: While patient-level factors have been previously investigated, this study aimed to evaluate regional variation in the receipt of curative-intent surgery for potentially curable gastric cancer in the United States. METHODS: Using the SEER-Medicare database, potentially curable gastric cancer patients diagnosed between 2011 and 2018 were identified. Crude rates of receiving surgery, defined as in-hospital gastrectomy or endoscopic resection, and adjusted for patient-level factors (age, T-stage, comorbidities) were calculated on the level of health service areas (HSAs). The proportion attributed to the total variance was calculated for four domains: patient-level factors, region (HSA), randomness, and unexplained factors. RESULTS: Of 6012 included patients (median [IQR] age, 78 [72-84] y), 3530 (58.7%) received surgery. Even when adjusting for patient-level factors, significant variation across 93 eligible HSAs was observed, ranging from 55.4% to 74.1%. The largest component explaining the variance in receiving curative-intent surgery was unexplained factors (42.1%), exceeding patient-level factors and region (HSA). CONCLUSIONS: Significant variation in receiving curative-intent surgery was observed across HSAs and future research should focus on identifying these unexplained factors.