Long-term survival after liver metastasectomy in gastric cancer: Systematic review and meta-analysis of prognostic factors

Background: Despite the amelioration of systemic therapy, overall survival (OS) of metastatic gastric cancer (GC) patients remains poor. Liver is a common metastatic site and retrospective series suggest a potential OS benefit from hepatectomy, with interesting 5-year (5 y) and 10-year (10 y) OS rates in selected patients. We aim to evaluate the impact of liver resection and related prognostic factors on long-term outcome in this setting. Methods: We searched Pubmed, EMBASE, and Abstracts/posters from international meetings since 1990. Data were extracted from publish papers. Random effects models meta-analyses and meta-regression models were built to assess 5yOS and the impact of different prognostic factor. Heterogeneity was assessed using between study variance, I2 and Cochran's Q. Funnel plot were used to assess small study bias. Results: Thirty-three observational studies (for a total of 1304 patients) were included. Our analysis demonstrates a 5yOS rate of 22% (95%CI: 18–26%) and 10yOS rate of 11% (95%CI: 7–18%) among patients undergoing radical hepatectomy. A favorable effect on OS was shown by several factors linked to primary cancer (lower T and N stage, no lympho-vascular or serosal invasion) and burden of hepatic disease (≤3 metastases, unilobar involvement, greatest lesion < 5 cm, negative resection margins). Moreover, lower CEA and CA19.9 levels and post-resection chemotherapy were associated with improved OS. Conclusions: Surgical resection of liver metastases from GC seems associated with a significant chance of 5yOS and 10yOS and compares favourably with results of medical treatment alone. Prospective evaluation of this approach and validation of adequate selection criteria are needed.