Abstract: Objective To investigate the prognostic impact of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) and CD34 on invasion and metastasis of gastric cancer. Methods CEACAM1 and CD34 expressions were detected by immunhistochemistry in 90 cases of gastric cancer and 30 cases of normal gastric mucosa. Then the relationship among CEACAM1, MVD marked by CD34 antibody and gastric cancer patients’ clinical pathological features and prognosis were analyzed. Results The positive rates of CEACAM1 and CD34 protein in gastric cancer were significantly higher than those in normal gastric mucosa (P＜0.05). The positive degree of CEACAM1 was closely associated with histological differentiation, tumor invasion, nodal metastasis and TNM stage. MVD marked by CD34 was related with tumor size, histological differentiation, tumor invasion, nodal metastasis and TNM stage（P＜0.05）. Conclusions In gastric cancer, CEACAM1 and CD34 promote its capability of invasion and metastasis, and they might be used as an indicator in predicting development and prognosis.

Key words: [Key words] carcinoembryonic antigen-related cell adhesion molecule 1, microvessel density, gastric cancer, immunhistochemistry