5.2.4. Immunotherapy

Immunotherapy was first proposed in 1909 by Nobel Prize winner Paul Ehrlich. The idea behind it is that immune cells can control malignant cells and eradicate cancers before they manifest clinically [35]. However, in spite of several mechanisms active in the immune system to recognize and eliminate tumor cells, some variants of these cells selectively acquire increased resistance against immune responses. Thereafter, resistant cells continue to grow, evading the immune responses, and tumor cells develop resistance against both innate and adaptive immune mechanisms (cancer immunoediting) [35]. To avoid cancer immunoediting, patients can be vaccinated (monoclonal antibodies, adaptive T cells, DNA viral vectors, heat shock proteins, and dendritic cells, among others [35,50–54]) to raise specific immune responses. Moreover, this therapy is followed in parallel with another adjuvant therapy to potentiate the immune system [35].
