Palliative gastrectomy for metastatic gastric adenocarcinoma: A national population-based cohort study

Background: The impact of palliative gastrectomy for metastatic gastric adenocarcinoma, especially by site of metastasis remains unclear.

Methods: The National Cancer Database, 2010–2015, was used to identify patients with clinical metastatic (cM1) gastric adenocarcinoma (n = 19,411) at diagnosis. The main variable was index management for cM1 gastric adenocarcinoma (ie, no treatment, palliative chemotherapy, or palliative gastrectomy). Cox multivariable analyses were used to account for treatment selection bias and reported as hazard ratio (HR) and 95% confidence interval.

Results: Of 19,411 patients, 10,893 (56%) received palliative chemotherapy, and only 1,101 (6%) received palliative gastrectomy only. The median survival was 6.1 months, and 5-year survival was 4% in the entire cohort. Patients receiving palliative gastrectomy had a significantly longer survival than patients without any treatment or palliative chemotherapy (median: 12.8 vs 1.8 vs 9.5 months, P < .001), which remained after multivariable adjustment (HR: 0.76, 95% confidence interval: 0.71–0.81, P < .001) compared with palliative chemotherapy. Stratified analyses by clinical nodal stage (cN) demonstrated survival benefit with palliative gastrectomy: cN0 (HR: 0.71, 95% confidence interval: 0.62–0.82), cN1 (HR: 0.68, 95% confidence interval: 0.59–0.79), cN2 (HR: 0.86, 95% confidence interval: 0.70–0.94), and cN3 (HR: 0.82, 95% confidence interval: 0.70–0.92) over palliative chemotherapy. Stratified analyses by metastasis site demonstrated that palliative gastrectomy remained superior compared with palliative chemotherapy for metastatic disease limited to liver, bone, and peritoneum, but equivalent to lung metastasis and inferior to brain metastasis.

Conclusion: Palliative gastrectomy appears to have a modest survival benefit over palliative chemotherapy alone. Differences in outcomes by site of metastasis warrant further research to understand tumor biology and identify specific subgroups which may benefit from palliative gastrectomy.