Gene therapy is a promising therapeutic tool for the treatment of diseases not eliminated by conventional treatment methods. Discoveries in the field of human genomics have, along with the significant technological advances, contributed to its application in the treatment of a wide range of diseases. Despite numerous studies and development of variety potential therapies, cancer remains the leading cause of death in the world. Therefore, a large number of clinical studies, that apply gene therapy strategies, are directed towards its reduction and elimination. Over the course of many years, a number of cancer gene therapy strategies have been proposed, most of which were clinically unsuccessful. However, over the last few years, a new form of immunotherapy has gained great attention in research due to high therapeutic efficacy. Therapy in question is CAR-T therapy that combines gene therapy, cell therapy and immunotherapy strategies. This paper provides a brief overview of some of the major gene therapy strategies for cancer treatment, with a special focus on adaptive CAR-T therapy. Also, the paper presents disadvantages and adverse side effects, as well as strategies for developing safer and more effective therapy.