Published online Jul 15, 2017. doi: 10.4251/wjgo.v9.i7.293
Peer-review started: October 23, 2016
First decision: December 20, 2016
Revised: February 2, 2017
Accepted: June 6, 2017
Article in press: June 8, 2017
Published online: July 15, 2017
Processing time: 264 Days and 16.1 Hours
Immunotherapy has begun to revolutionize cancer treatment, by introducing therapies that target the host immune system instead of the tumor, therapies that possess unique adverse event profiles, and therapies that may cure certain types of cancer. The immune microenvironment of tumors is emerging as the most important means of understanding the relationship between a patient’ immune system and their cancer, informing prognosis, and guiding immunotherapy, such as an antibody blockade of immune checkpoints. For some solid tumors, simple quantitation of lymphocyte infiltration would seem to have prognostic significance, suggesting that lymphocyte infiltration is not passive but may actively promote or inhibit tumor growth. For gastric cancers, several studies have provided strong evidence that immune cells contribute to determining prognosis. However, the exact role of immune cells in gastric cancer remains unclear. Therefore, this review focuses on the clinical significance of immune cells, especially tumor-infiltrating lymphocytes, in gastric cancer.
Core tip: Tumor-infiltrating lymphocytes (TILs) are considered a manifestation of the host immune response against tumor cells, and several studies have already reported the potential of TILs as a prognostic parameter for various human malignancies. However, only a few studies have investigated the prognostic impact of TILs in gastric cancer. Based on a comprehensive molecular characterization of gastric cancer, TILs could be a potential biomarker. Accordingly, this review focuses on the clinical significance of immune cells, especially TILs, in gastric cancer.