Immunological mechanisms underneath the efficacy of cancer therapy

Accumulating preclinical and clinical evidence indicates that the success of several anticancer agents-including some conventional chemotherapeutics, targeted anticancer agents as well as specific forms of radiotherapy-depends (at least in part) on their ability to stimulate anticancer immune responses. Such immunostimulatory effects can be "on-target," i.e., they originate within cancer cells, or "off-target," i.e., they develop from a heretofore unsuspected interaction between cancer therapy and the immune system. Here, we briefly discuss the immunologic mechanisms that underlie the efficacy of some forms of cancer therapy, as we highlight the rationale for combining these treatment modalities with immunotherapy to achieve superior therapeutic effects.