Current Status of Immune Checkpoint Inhibitors in Gastrointestinal Cancers

The expansion of our understanding of tumor immunity and the recent success of new cancer immunotherapy has reignited the hope that we can treat cancer effectively with immunotherapeutic approaches. Immune checkpoint inhibitors have shown significant efficacy in the treatment of some solid and hematologic malignancies. Encouraged by recent success in some other types of malignancies, many clinical trials are ongoing to evaluate the efficacy of immune checkpoint inhibitors in gastrointestinal (GI) malignancies. In this review, we briefly discuss theoretical background and current status of immune checkpoint inhibitors in GI cancers. We summarize the key studies and present the ongoing clinical trials involving immune checkpoint inhibitors in GI cancers.