We evaluated in 74 patients with resectable primary gastric carcinoma, the prognostic value of the preoperative circulating serum levels of CEA and TAG-72. Serum levels of CEA were above the cutoff level of 6 ng/ml in 18.9% of patients; TAG-72 levels were higher than 6 U/ml in 31% of patients. Pretreatment mean CEA levels were significantly lower (p < 0.01) in patients with stage I tumors (2.9 +/- 0.3 ng/ml) than in those with more advanced tumors (stage II: 14.5 +/- 6.8 ng/ml; stage III-IV: 6.8 +/- 1.5 ng/ml). Similarly, significant differences in mean TAG-72 serum levels were found between stage I (3.5 +/- 1.8 U/ml) and stage II and stage III-IV (30.4 +/- 20.7 U/ml and 26.1 +/- 9.7 U/ml, respectively) (p < 0.05). In addition, TAG-72 levels were also higher in poorly differentiated and moderately differentiated tumors (38.5 +/- 20.1 U/ml and 23.1 +/- 9.4 U/ml, respectively) than in well differentiated tumors (4.4 +/- 0.9 U/ml) (p < 0.05). The results further indicated that high preoperative serum levels of CEA predicted shorter relapse-free survival duration (p < 0.01), and that high TAG-72 levels were associated with shorter relapse-free and overall survival (p < 0.0001 and p < 0.0005, respectively). In addition, separate Cox multivariate analysis showed that preoperative TAG-72 was, after stage, the strongest factor to predict both relapse-free and overall survival (p < 0.0001 and p < 0.005, respectively) in patients with gastric cancer.