Adapting conventional cancer treatment for immunotherapy

The efficacy of directly killing tumors by conventional cancer therapies, such as chemotherapy and radiotherapy, has been for several decades well established. But, a suppressed immune response might become a lethal side effect after repeated cycles of intensive treatment. Recently, achievements in immune checkpoint inhibitors and adoptive T cell-mediated immunotherapies have resulted in changes in frontline management of advanced cancer diseases. However, accumulated evidence indicates that immunotherapeutic and conventional strategies alone are often ineffective to eradicate big tumors or metastasis. To improve the outcomes of treatment for advanced cancer diseases, the combination of conventional cancer treatment with various immunotherapeutic approaches has been attempted and has shown potential synergistic effects. Recent studies have unexpectedly demonstrated that some strategies of conventional cancer treatment can regulate the immune response positively, thus the understanding of how to adapt conventional treatment for immunotherapy is crucial to the design of effective combination therapy of conventional treatment with immunotherapy. Here, we review both experimental and clinical studies on the therapeutic effect and its mechanisms of combining conventional therapy with immunotherapy in treatment of cancer.