Prognostic role of lemur tyrosine kinase 3 in postoperative gastric cancer.

The treatment of gastric cancer has been unsatisfactory thus far; therefore, novel targets and treatment strategies are urgently required. Lemur tyrosine kinase (LMTK)3 is an estrogen receptor-α (ERα) modulator with a central role in endocrine resistance in breast cancer. Moreover, the expression and polymorphisms of LMTK3 are correlated with the prognosis of breast cancer patients. Since estrogen receptor (ER) is also expressed and plays a role in gastric cancer, we herein investigated the expression of the LMTK3 protein in 83 gastric cancer patients by tissue microarray and analyzed the correlation between LMTK3 expression and the prognosis of gastric cancer. Our results demonstrated that LMTK3 was more frequently expressed in gastric cancer tissues compared to non-cancerous mucosa (79.5 vs. 45.8%, respectively; P=0.000). The LMTK3 expression was significantly correlated with the depth of invasion (P=0.002) and disease stage (P=0.035). The Kaplan-Meier analysis revealed that the postoperative survival of the LMTK3-negative group was superior to that of the LMTK3-positive group (P=0.043). Moreover, the multivariate analysis identified LMTK3 expression as an independent prognostic factor for patients with gastric cancer (P=0.019). These findings suggested that the expression of LMTK3 may be a negative prognostic factor in patients with gastric cancer. Moreover, targeting LMTK3 is a potential strategy for the treatment of gastric cancer, although the biological functions of LMTK3 in gastric cancer require further investigation.