Anticancer Immunotherapy: Prospects And Challenges

Accumulating evidence indicates that immune cells in the microenvironment play a significant role in tumor progression. Understanding the dynamic interplay between tumor cells and the host immune system is therefore of critical importance. While some immunotherapeutic strategies aim to specifically overcome hyporesponsiveness to tumor-associated antigens, others seek to nonspecifically activate the immune system; efficacy and toxicity are overriding, and often conflicting, concerns. This chapter, while occasionally providing brief historical perspectives, describes ongoing efforts in the area, including strategies for anticancer vaccination and adoptive cell transfer, the use of cytokines and development of oncolytic viruses, and the administration of checkpoint inhibitors. While significant successes have been achieved, the field is also characterized by notable failure, an indication that much remains unknown about factors that trigger and promote tumorigenesis, about current limitations in the effective delivery of therapeutic moieties, and about the workings of the immune system.