Clinicopathologic and Prognostic Value of Serum Carbohydrate Antigen 19-9 in Gastric Cancer: A Meta-Analysis

BACKGROUND The clinical value of carbohydrate antigen (CA) 19-9 in gastric cancer is controversial. We evaluated the clinicopathologic and prognostic value of CA 19-9 in gastric cancer. METHODS A literature search was conducted in PubMed and Embase databases. Odds ratios (ORs), risk ratios (RR), hazard ratios (HRs), and 95% confidence intervals (CIs) were used as effect measures. RESULTS Thirty-eight studies were included. Results showed that there were significant differences in the incidence of high CA 19-9 levels between stages III/IV and I/II groups (OR = 3.36; 95% CI = 2.34-4.84), the pT3/T4 and pT1/T2 groups (OR = 2.40; 95% CI = 1.60-3.59), the lymph node-positive and node-negative groups (OR = 2.91; 95% CI = 2.21-3.84), the metastasis-positive and metastasis-negative groups (OR = 2.76; 95% CI = 1.12-6.82), and vessel invasion-positive and invasion-negative groups (OR = 1.66; 95% CI = 1.11-2.48). Moreover, CA 19-9 was significantly associated with poor overall survival (HR = 1.83; 95% CI = 1.56-2.15), disease-free survival (HR = 1.85; 95% CI = 1.16-2.95), and disease-specific survival (HR = 1.33; 95% CI = 1.10-1.60) in gastric cancer. CONCLUSIONS Our meta-analysis showed that CA 19-9 indicates clinicopathologic characteristics of gastric cancer and is associated with a poor prognosis.