[The biological rationale for immunotherapy in cancer].

Introduction: Immunotherapy aims to promote the immune system's activity against malignant cells by stimulating the response to several tumor antigens.
State of the Art: Immunosurveillance may adjust the immunogenicity of tumors. To be effective, immunity must induce the specific activation of CD4+ and CD8+ T lymphocytes, as well as activation of innate immunity. Activator and inhibitory costimulatory molecules regulate T lymphocyte activation at immunity checkpoints such as PD-1/PD-L1 and CTLA-4. Adaptive immune resistance confers tumour resistance to immunosurveillance through these immune checkpoints.
Perspectives: Approaches involving the combination of several immunotherapies with each other or with chemotherapy and radiotherapy and antibodies against other molecules of costimulation are under development. The development of biomarkers, which can select a targeted population and predict therapeutic response, represents a major challenge. Tumour high-throughput sequencing could refine "immunoscore". Intratumoral T cell receptor seems to represent a promising biomarker.
Conclusions: Numerous challenges still remain in developing research approaches for the development of immunotherapies.
(Copyright © 2018 SPLF. Published by Elsevier Masson SAS. All rights reserved.)