Surgical resection of metachronous hepatic metastases from gastric cancer improves long-term survival: A population-based study

INTRODUCTION: Hepatic metastases are diagnosed synchronously in 3–14% of patients with gastric cancer, and metachronously in up to 37% of patients following ‘‘curative” gastrectomy. Most patients who have gastric cancer and hepatic metastasis are traditionally treated with palliative chemotherapy. The impact of liver resection is still controversial. We attempted to assess whether liver resection can improve survival in cases of metachronous hepatic metastases from gastric cancer through a nationwide database. MATERIALS AND METHODS: We conducted a nationwide cohort study using a claims dataset from Taiwan’s National Health Insurance Research Database (NHIRD). We identified all patients with gastric cancer (diagnostic code ICD-9: 151.x) from the Registry for Catastrophic Illness Patient Database (RCIPD) of the NHIRD who received gastrectomy and as well as those with metachronous (≥180 days after gastrectomy) liver metastases (ICD-9 code: 197.7) between 1996/01/01 and 2012/12/31. Patients with other malignancies, with metastasis in the initial admission for gastrectomy and with other metastases were excluded. They were divided into two groups, liver resection group and non-resection group. All patients were followed till 2013/12/31 or withdrawn from the database because of death. RESULTS: 653 patients who fullfilled the inclusion criteria were included in the research. They were divided into liver resection group (34 patients) and non-resection group (619 patients). There were no differences between the two groups in gender, Charlson Comorbidity index and major coexisting disease. Kaplan-Meier analysis demostrated the liver resection group had significantly better overall survival than the non-resection group. (1YOS: 73.5% vs. 19.7%, 3YOS: 36.9% vs. 6.6%, 5YOS: 24.5.3% vs. 4.4%, p <0.001). After COX analysis, the liver resection group showed statistical significance for improved patient survival (HR = 0.377, 95%CI: 0.255–0.556. p<0.001). CONCLUSION: Liver resection in patients presenting with metachronous hepatic metastases as the sole metastases after curative resection of gastric cancer is associated with a significant survival improvement and should be considered a treatment option for such patients.