Immunotherapy of Gastric and Esophageal Cancers

Gastric and esophageal cancers contribute to significant health burden and cancer-related mortality worldwide. Despite recent advances in diagnostic and therapeutic modalities, patients are still diagnosed at late stages and have low rates of survival. Recently, immunotherapeutic modalities have shown promising results in improving survival of patients when used as a single agent or in combination with conventional chemotherapy. Gastric and esophageal cancers have higher response rates to immunotherapy compared to other GI cancers. Monoclonal antibodies against vascular endothelial growth factor receptor (e.g., ramucirumab) and epidermal growth factor receptor 2 as well as protein-based vaccine are some good examples. For other modalities such as adoptive cellular therapy and immune checkpoint inhibitors, more work is needed to reach conclusive results. Molecular and genetic subtype of the tumor and the extent of tumor infiltration by cytotoxic T lymphocytes are some of the main factors that influence response to immunotherapeutic treatment. In this chapter, we review the last updates on current immunotherapeutic modalities against gastric and esophageal cancers.