Developing rational combinations of immune checkpoint inhibitors and radiation therapy for gastrointestinal cancers.

Evidence supporting the synergistic antitumor activity of radiation therapy combined with immune checkpoint inhibitors is rapidly growing. Investigators should consider the characteristics and challenges of gastrointestinal (GI) cancers to evaluate the safety and clinical effectiveness of this combination. In this paper, we present the rationale for exploring this strategy and the opportunities it possesses to challenge our standard of care. We also discuss unique considerations to systematically develop this combination in GI cancers.