Prognostic significance of malignant ascites in gastric cancer patients with peritoneal metastasis: A systemic review and meta-analysis

BACKGROUND: Recent evidence indicates that malignant ascites may be associated with the high malignancy and poor prognosis of gastric cancer (GC) with peritoneal metastasis (PM), but no robust consensus has been reached until now. AIM: To evaluate the prognostic significance of malignant ascites in GC patients with PM. METHODS: Two independent authors conducted database searches. The searches were performed in the EMBASE, PubMed, and Cochrane Library databases, and the terms used to search included stomach neoplasms, GC, ascites, peritoneal effusion, survival, and survival analysis. Outcomes included overall survival and hazard ratios with 95% confidence intervals (CIs). Three pairs of comparisons for measuring survival were made: (1) Patients with ascites vs those without ascites; (2) Patients with massive ascites vs those with mild to moderate ascites; and (3) Patients with massive ascites vs those with no to moderate ascites. RESULTS: Fourteen articles including fifteen studies were considered in the final analysis. Among them, nine studies assessed the difference in prognosis between patients with and without malignant ascites. A pooled HR of 1.63 (95%CI: 1.47-1.82, P < 0.00001) indicated that GC patients with malignant ascites had a relatively poor prognosis compared to patients without ascites. We also found that the prognosis of GC patients with malignant ascites was related to the volume of ascites in the six other studies. CONCLUSION: GC patients with malignant ascites tend to have a worse prognosis, and the volume of ascites has an impact on GC outcomes.