Prognostic implications of organ-specific metastases in advanced gastric cancer: A retrospective observational analysis of the SEER database

Advanced gastric cancer (GC) remains a significant global health burden with poor prognosis. Understanding organ-specific metastatic patterns and their prognostic implications is critical for optimizing patient management. This study leverages the Surveillance Epidemiology and End Results database to comprehensively analyze metastatic patterns in GC and develop a robust prognostic model. We analyzed data from 10,842 GC patients diagnosed between 2010 and 2014, focusing on metastases to the liver, lungs, bones, and brain. Metastatic patterns, prognostic outcomes, and risk factors were evaluated using multivariable logistic and Cox regression analyses. A nomogram was developed to predict overall survival. Liver metastases were the most common (40.5%), followed by lung (13.5%), bone (11.0%), and brain (1.7%). Dual-organ metastasis most frequently involved the liver and lungs. Patients with isolated liver metastases had a relatively better prognosis (hazard ratio = 1.29, 95% confidence interval = 1.23-1.36, P < .0001), while those with isolated bone metastases had the poorest outcomes (hazard ratio = 1.99, 95% confidence interval = 1.63-1.96, P < .0001). Prognosis was uniformly poor for patients with metastases to 2 or more organs. Key risk factors included male sex, older age, and poorly differentiated tumors. A nomogram incorporating these factors demonstrated strong predictive accuracy. This study provides a comprehensive analysis of organ-specific metastatic patterns in GC, highlighting the prognostic significance of metastatic sites. The developed nomogram offers a practical tool for clinicians to predict survival outcomes and tailor treatment strategies for advanced GC patients.