Serum CA 19‐9 as a prognostic factor in patients with metastatic gastric cancer

AIM: To evaluate tumor markers as prognostic factors in patients with metastatic or recurrent gastric cancer receiving first-line chemotherapy. METHODS: Between January 2000 and December 2008, 1178 patients with metastatic or recurrent gastric cancer were assayed for expression of three serum tumor markers, CA 19-9, CA 72-4 and carcinoembryonic antigen (CEA), prior to the initiation of first-line chemotherapy. RESULTS: Elevated serum concentrations of carbohydrate antigen (CA) 19-9 (>37 U/mL), CA 72-4 (>4 U/mL) and carcinoembryonic antigen (CEA) (>6 ng/mL) were observed in 38, 56 and 33% of patients, respectively. Univariate analysis showed that elevated serum concentration of each of the three markers, CA 19-9 (P = 0.001), CA 72-4 (P = 0.001) and CEA (P = 0.030), was significantly associated with poor patient prognosis. However, multivariate analysis showed that an elevated CA 19-9 concentration only was significantly associated with shorter survival (hazard ratio [HR] 1.22; 95% CI, 1.08-1.37, P = 0.002). In the good risk and moderate risk groups, previously defined by clinical factors alone, survival was significantly lower in patients with elevated CA 19-9 (P < 0.001 and P = 0.021, respectively), but this difference was not observed in the poor-risk group. CONCLUSION: Elevated serum CA 19-9 concentration in patients with metastatic or recurrent gastric cancer, especially in good or moderate risk groups, is an independent negative predictor of prognosis.