Relevance of Further Clinical Trials of the Use of Melatonin in Adjuvant Cancer Therapy

Abstract

The review was compiled from a PubMed, Web of Science, Scopus and Google search, which showed a lack of information on clinical studies of melatonin (M) in oncology, despite numerous and promising experimental results. In preliminary clinical studies carried out by P. Lissony and his co‑authors, the therapeutic potential of M as an adjuvant in chemotherapy, radiation therapy and immunotherapy at different tumor localizations is noted. M alleviates the toxic effect of standard therapy and, according to the authors’ observations, increases its effectiveness. Exogenous M can be in demand as a circadian rhythm synchronizer for rehabilitation and im‑ provement of the quality of life of patients, because reduces distress and improves sleep, and in supportive and palliative therapy. Oncostatic activity of M is associated with the effect on: a) homeostasis and circadian rhythms, b) inflammation, cooperation of immunocytes and cytokine production in the tumor microenvironment, c) gene expression and signalling pathways associated with angiogenesis, proliferation and metastasis, d) metabolism, hypoxia and oxidative stress, e) apoptosis and resistance to chemotherapy and radiation therapy. The review contains the following sections: physiological and pharmacological studies, epidemiological studies, clinical studies, the immunoregulatory role of melatonin, experimental studies. Currently, randomized and long‑term clinical studies of homogeneous groups of patients with tumor stages II−III are in demand for statistical processing of information of the M influence on the side effects of standard therapy, on the dy‑ namics of the disease, clinical parameters, as well as on the quality and duration of life after the main treatment.