Expression and clinical significance of stem cell marker Lgr5 protein in human gastric carcinoma

Objective To investigate the expression and its significance of Lgr5 protein in gastric cancer. Methods Lgr5 expression was detected by immunohistochemistry in normal tissues, paracancerous tissues and gastric cancer tissues of 70 patients with gastric cancer treated from January 2012 to June 2015. Clinicopathological information and prognosis data of these 70 patients were analyzed to figure out the role of Lgr5 in gastric cancer. Results The expression rate of Lgr5 in tumor tissues (50/70, 71.4%) was significant higher than that in both normal tissues (21/70, 30.0%, χ2=24.034, P=0.000) and paracancerous tissues (35/70, 50.0%, χ2=6.738, P=0.009). Lgr5 expression was significantly correlated with TNM stage and lymph node metastasis. There was no correlation between expression of Lgr5 with age, differentiation, and clinical characteristics in gastric cancer. Kaplan-Meier analysis showed significant difference in 3-year survival rates between groups with and without Lgr5 expression (χ2=3.929, P=0.047). Conclusions Expression of Lgr5 in gastric cancer indicates that stem cells may be involved in the pathogenesis of gastric cancer and Lgr5 may play an important role in the development and progression of gastric cancer. Lgr5 expression might be a useful marker of poor prognosis in gastric cancer. Key words: Stomach neoplasms; Stem cell; Leucine; G-protein-coupled receptor kinase 5