Survival benefits of palliative gastrectomy in stage IV gastric cancer: a propensity score matched analysis

Background: This study aimed to investigate the effect of palliative gastrectomy on survival in stage IV gastric cancer. Methods: Patients diagnosed with stage IV gastric cancer between 2010 and 2016 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Survival curves were estimated by the Kaplan-Meier method before and after propensity score matching (PSM). Univariate and multivariate Cox analyses were performed to evaluate risk factors for survival in patients who underwent palliative gastrectomy. Results: We examined 6,529 patients with stage IV gastric cancer, of which 625 underwent palliative gastrectomy. Using a 1:2 PSM, the 625 patients were matched with 1,250 patients from the no gastrectomy group. The overall survival was higher in the gastrectomy group before [hazard ratio (HER) =0.57, 95% confidence interval (CI): 0.53-0.62, P<0.0001] and after PSM (HR =0.51, 95% CI: 0.46-0.57, P<0.0001). Multivariate Cox analysis confirmed the survival benefits of palliative gastrectomy and chemotherapy. Older age, over-lapping lesions, non-adenocarcinomas, higher tumor grade, and lung metastasis significantly increased the risk of mortality. In the gastrectomy group, patients aged >= 80 years, diagnosed with grades 3/4 non-adenocarcinomas, or with lung metastasis showed poorer prognosis. However, chemotherapy could improve the survival of these patients. Conclusions: Palliative gastrectomy provides survival benefits to stage IV gastric cancer patients. However, age, tumor grade, tumor histology, and lung metastasis status should be considered while making a decision regarding gastrectomy. Chemotherapy should also be recommended for these patients.