Developments in the understanding of T-cell biology and immune-tumor cell interactions have ushered in a new age in cancer immunotherapy. In its most sophisticated form, cancer goes through 3 phases called elimination, equilibrium, and escape, and a framework called cancer immunoediting was established 20 years ago to help make sense of this dynamic process. Tumors go through immunoediting as cancer develops through various stages, making them less immunogenic and more able to set up an immunosuppressive microenvironment. Therefore, cancer immunoediting sculpts immunogenicity beyond modifying antigenicity by integrating the complex immune-tumor cell interactions happening in the tumor microenvironment. In recent years, however, the term “cancer immunoediting” has been inappropriately limited to describing neoantigen loss by immunoselection, despite the fact that cancer immunotherapy has resulted in durable clinical responses in the last decade and the subsequent emergence of immuno-oncology as a clinical subspecialty. This has diverted attention away from the fact that cancer immunoediting can also affect tumor immunogenicity through other methods. Although preclinical models without immunotherapy were used to establish the idea of cancer immunoediting and provide clear experimental evidence supporting its presence, cancer immunoediting is a continuous process that also happens during immunotherapy in people with cancer. Here, researchers review the preclinical and clinical evidence for cancer immunoediting processes and focus on how a deeper knowledge of cancer immunoediting may provide light on the causes of and potential solutions to immunotherapy resistance.
