Selective survival advantage associated with primary tumor resection for metastatic gastric cancer in a Western population.

ABSTRACT

BACKGROUND: The prognosis of metastatic gastric cancer (GC) remains dismal, with a median survival of 10 months. Historically, primary tumor resection was not thought to confer any survival benefit. Although high-level data exist guiding treatment of metastatic GC for patients in the East, no such data exist for Western patients despite inherent ethnic differences in GC biology. METHODS: The 2006-2012 National Cancer Database was queried for adult patients with metastatic gastric adenocarcinoma. Patients were classified into those who underwent primary tumor resection and chemotherapy (PTRaC) and those who received chemotherapy only. Groups were propensity score matched, and survival was compared using advanced statistical modeling. RESULTS: A total of 7026 patients met the inclusion criteria 6129 (87%) patients were treated with chemotherapy alone and 897 (13%) patients were treated with PTRaC. After multivariable adjustment, patients who underwent PTRaC had a significantly better overall survival (OS) than patients who received systemic therapy only (HR, 0.60; 95% CI, 0.56-0.64; p < 0.001). Following full bipartite propensity score-adjusted analysis, 2-year OS for patients who received chemotherapy only was 12.6% (95% CI, 11.7-13.5%), whereas it was 34.2% (95% CI, 31.3-37.5%) for patients who underwent PTRaC (HR for resection 0.52; 95% CI, 0.47-0.57; p < 0.001). CONCLUSION: Our data suggest that there exists a subset of patients with metastatic GC for which PTRaC may improve OS. As significant uncertainty still remains, our results support the need for further prospective trials investigating the influence of palliative gastrectomy on survival among Western patients.