ObjectiveTo detect expressions of Lgr5 and E-cadherin (E-cad) proteins in gastric cancer tissues and analyze their relationships with the clinicopathologic characteristics and prognosis of patients with gastric cancer.MethodsThe expressions of Lgr5 and E-cad proteins in the 69 patients with gastric cancer and adjacent normal gastric mucosa tissues were measured by the immunohistochemical SABC method, and the relationships between the Lgr5 or E-cad protein expression in the gastric cancer tissues and the clinicopathologic characteristics and the survival of patients with gastric cancer were analyzed.ResultsThe expressions of Lgr5 and E-cad proteins were positive in 60 cases (87.0%) and 30 cases (43.5%) of gastric cancer tissues, respectively, and in 5 cases (16.7%) and 30 cases (100%) of adjacent normal gastric mucosa tissues. There was a significant difference in the positive rate of Lgr5 or E-cad protein expression in the different tissues, respectively (Lgr5 protein: χ2=45.814, P<0.001; E-cad protein: χ2=11.249, P=0.001). The positive rates of Lgr5 and E-cad protein expressions in the gastric cancer were related to the degree of differentiation and the depth of invasion. Meanwhile the positive rate of Lgr5 protein expression in the gastric cancer tissue was also related to the lymph node metastasis and Helicobacter pylori infection, while the positive rate of E-cad protein expression was not related to these (P>0.05). The 5-year total survival time had no significant difference in the patients between with positive and with negative expressions of Lgr5 protein (χ2=1.819, P=0.117), which had a significant difference in the patients between with positive and with negative expressions of E-cad protein (χ2=5.814, P=0.016). The positive expression of Lgr5 was negatively correlated with that of E-cad (rs=−0.355, P=0.003).ConclusionsLgr5 protein may get involved in the mechanism of tumor invasion, lymph nodal metastasis, and low differentiation, while no relationship between the Lgr5 protein and prognosis has been confirmed. E-cad protein may get involved in the mechanism of tumor invasion and affect the prognosis of patients.