Objective   To investigate the expression of the immune checkpoint lymphocyte-activation gene 3 (LAG-3), fibrinogen-like protein 1 (FGL1), and major histocompatibility complex class II (MHC-II) in gastric antral cancer (GAC) and determine their correlation with disease prognosis.

  Methods   The expression of LAG-3, FGL1, and MHC-II was analyzed in 67 patients with GAC admitted to Tianjin Medical University Cancer Institute & Hospital from January 2012 to December 2014 using immunohistochemistry. Variations between the groups were analyzed using statistical methods. The Kaplan-Meier method was used to evaluate the relationship between the LAG-3, FGL1, and MHC-II expression levels and the prognosis of patients with GAC.

  Results   LAG-3 expression level in immune cells was higher in patients with GAC presenting with a tumor size of <4 cm and in those without lymph node metastasis (P<0.05). Further, MHC-II expression level in immune cells was higher in female than in male patients (P<0.05). Patients with high LAG-3 and MHC-II expression levels in immune cells had better overall survival (OS, P<0.05); whereas, patients with high MHC-II expression levels in tumor cells had worse OS and disease-free survival (DFS, P<0.05). However, FGL1 expression in immune cells and tumor cells was not significantly correlated with OS and DFS (P>0.05).

  Conclusions   The LAG-3 and MHC-II expression levels in various regions of patients with GAC differ, and the expression of LAG-3 and its ligands in the immune cells of patients have a positive impact on prognosis. This suggests that LAG-3 and MHC-II in immune cells can be used as prognostic markers of GAC, providing a novel basis for individualized clinical immunotherapy.