Conclusion

Although it is possible to encounter descriptions of the influence of psychosocial factors on the development and progression of cancer as early as Galen’s Treatise, it is only since the turn of the twentieth and twenty-first centuries that research into the interactions between the nervous system and tumors has seen a significant acceleration. This is due to a number of factors, such as the accumulation of a critical mass of knowledge that has made it possible to postulate new hypotheses regarding interactions between the nervous system and the tumor process, as well as the introduction of new sophisticated scientific research methods. Thanks to this, a relatively large amount of new knowledge has accumulated in the last two decades about the mechanisms and pathways that, on the one hand, allow the brain to modulate processes related to tumorigenesis, tumor cell proliferation, and metastasis formation and, on the other hand, allow tumor tissue to manipulate the host nervous system.