Systemic therapy for esophagogastric cancer: immune checkpoint inhibition
The poor prognosis for patients with esophagogastric cancers (EGC) requires the development of newer more effective therapies to further improve the treatment outcomes for this disease. Immunotherapy is a novel treatment strategy that is dramatically changing the treatment landscape for several types of cancers. Cytotoxic T lymphocyte antigen-4 (CTLA-4) and programmed death (PD)-1/PD-ligand are essential immune checkpoint inhibitors that suppress T cell activation. Targeting of these immune checkpoints with monoclonal antibodies has shown clinical efficacy in several solid tumors which has led to their approval and use in routine clinical practice. In EGC early phase evaluation of immune checkpoint inhibitors has yielded encouraging results with multiple phase 3 studies currently ongoing. In this review, the biological rationale for the use of immune checkpoint inhibitors in cancer will briefly be described and the accumulating data concerning their use in EGC will be presented.