Decreased Expression of Tumor-suppressor Gene LKB1 Correlates with Poor Prognosis in Human Gastric Cancer

Background/Aim: The present report describes the correlation of liver kinase B1 (LKB1) expression with tumorigenesis and prognosis in gastric cancer. Materials and Methods: LKB1 mRNA and protein expression was detected in gastric-cancer cell lines and patient specimens. Patients were followed-up and clinico-pathological parameters and overall survival (OS) were evaluated. Results: The expression of LKB1 mRNA and protein was lower in gastric-cancer cell lines and tumor tissues compared to normal gastric cells (p<0.05) and tissues (p<0.001). Decreased expression of LKB1 mRNA and protein in patients with gastric cancer was significantly inversely related to TNM stage, T-stage (depth of invasion), lymph-node metastasis and vascular invasion (p<0.05). Patients showing high LKB1 mRNA and high LKB1 protein expression had a significantly longer OS and better 5-year survival rate than those with low mRNA expression (61.3 months vs. 56.1 months and 75% vs. 58.7%, p<0.05, respectively) and low protein expression (64.8 months vs. 55.7 months and 72.9% vs. 64.5%, p<0.05, respectively). Multivariate Cox regression analysis indicated that both LKB1 mRNA and protein expression in gastric cancer were independent prognostic factors for OS. Conclusion: Patients with gastric cancer with decreased expression of LKB1 have a poor prognosis with a lower survival rate.