The clinical significance of ascitic fluid CEA in advanced gastric cancer with ascites

Background: This study was carried out to evaluate the clinical significance of ascitic fluid carcinoembryonic antigen (CEA) in advanced gastric cancer patients with ascites. Patients and methods: From November 2001 to February 2008, 119 gastric cancer patients with concurrent ascites who were clinically diagnosed with carcinomatosis, were retrospectively reviewed with regard to ascitic fluid cytology and clinicopathological parameters. Serum CEA (sCEA) and ascitic fluid CEA (aCEA) were measured using a chemiluminescent enzyme immunoassay. Results: The patients' median age was 50 years (range 23-80 years). The median value of aCEA was significantly higher than sCEA [130.5 ng/ml (range 0.2-12.211 ng/ml) vs. 2.1 ng/ml (range 0.02-8.152 ng/ml), p < 0.001]. Sixty-five patients (54.6%) had positive ascitic fluid cytology. The median overall survival of all patients was 3.0 months (95% CI 2.0-4.0 months). The patients with low aCEA (<5 ng/ml) had a significantly longer overall survival compared to patients with high aCEA (≥5 ng/ml) (7.4 months vs. 2.3 months, p = 0.003). However, we found no difference in overall survival according to ascitic fluid cytology (median, 3.0 months vs. 2.5 months, p = 0.530). Multivariate analysis also demonstrated that aCEA levels of more than 5 ng/ml were associated with poor prognosis (HR = 2.88; 95% CI 1.45-5.74; p = 0.003), while sCEA levels were not associated with poor prognosis (HR = 1.15; 95% CI 0.67-2.03; p = 0.622). Conclusion: These results suggest that aCEA levels can be used as a prognostic marker for advanced gastric cancer patients with ascites.