The psychoneuroendocrine-immunotherapy of cancer: Historical evolution and clinical results

The prognosis of the neoplastic diseases depends not only on the biogenetic characteristics of cancer cells but also on the immunological response of patients, which may influence the biological features of cancer cells themselves as well as the angiogenic processes. Moreover, the immune system in vivo is under a physiological psychoneuroendocrine (PNE) regulation, mainly mediated by the brain opioid system and the pineal gland. In more detail, the anticancer immunity is stimulated by the pineal hormone melatonin (MLT) and inhibited by the opioid system, namely, through a mu-opioid receptor. Several alterations involving the pineal endocrine function and the opioid system have been described in cancer patients, which could play a role in tumor progression itself. Therefore, the pharmacological correction of cancer progression-related anomalies could contribute to control cancer diffusion, namely, the pineal endocrine deficiency and the hyperactivity of brain opioid system. In fact, the administration of pharmacological doses of the only MLT has already been proven to prolong the 1-year survival in untreatable metastatic cancer patients. Better results may be achieved by associating other pineal indoles to MLT, mu-opioid antagonists, cannabinoids, beta-carbolines. Moreover, these neuroendocrine combinations may be successfully associated with antitumor cytokines, such as interleukin (IL)-2 and IL-12, as a PNE-immune cancer therapy as well as with antitumor plants as PNE-phytotherapy of cancer in an attempt to propose possible anticancer treatments also to patients with disseminated cancer and untreatable according to the standard oncology.