Combination of immune checkpoint inhibitors and radiotherapy: review of the literature

Literature experiences in cancer treatment usually deal with either targeting the tumour cell or the immune system, which often fail to reach the curative purposes in many solid tumours. On the other hand, one mechanism of radiation-induced tumour control is the activation of the adaptive immune system by tumour antigen release following radiotherapy. So, combining radiation therapy with immune checkpoint blockade treatment at the same time may represent a way to stimulate the adaptive immune system, with further amplification of immune responses reached through systemic immune checkpoint blockade. Until now, only few studies deal with the association of immune checkpoint blockade treatment and radiotherapy. In this review, we evaluate this association, highlighting this possibility as a new strategy to improve outcome in cancer patients.