Immunotherapy in Colorectal Cancer: Where Are We Now?

Abstract

This review examines the current state of colorectal cancer (CRC) immunotherapy across multiple treatment modalities and discusses some of the most promising approaches. CRC immunotherapy involving viral vector and dendritic cell vaccines, checkpoint blockade, and adoptive cell therapy has been explored from preclinical to clinical studies. Despite successes in other malignancies, including melanoma, leukemia, lung, and renal cancers, immunotherapies have been FDA approved for only a small subset of CRCs. Recent studies leveraging greater understanding of cellular and molecular mechanisms underlying colorectal tumorigenesis and immunotherapeutic mechanism of action may be exploited in upcoming trials. While immune infiltration of CRC has been an established indicator of patient outcomes, immunotherapeutic strategies to date have not exploited its potential immunogenicity to benefit patients. New vaccine, checkpoint inhibitor, and CAR-T cell therapy paradigms promise to change that. With continued research, we could see a rapid increase in the number of FDA-approved immunotherapies for CRC in the coming years.