Salivary Melatonin Changes in Oncological Patients: A Systematic Review

Abstract

Melatonin is known as a regulator of circadian sleep and waking rhythm. This hormone secreted by the pineal gland also has protective, oncostatic, and antioxidant properties. This systematic review was designed to answer the question “Is there a relationship between salivary melatonin changes and oncological diseases?”. Following the inclusion and exclusion criteria, ten studies were included, according to PRISMA statement guidelines. In all included studies, the diagnostic material was unstimulated whole saliva, in which the melatonin changes were determined by different laboratory methods. Most studies concerned changes in melatonin levels in patients with brain tumours due to a direct effect on the circadian rhythm centres. Other studies focused on disorders of melatonin secretion and its inclusion as a diagnostic marker in patients with prostate cancer and oral squamous cell carcinoma. The association between melatonin changes and sleep quality and chronotype in patients with newly diagnosed lung cancer and lymphoma survivors was also investigated. In conclusion, our systematic review may suggest trends for melatonin secretion alterations in oncological patients. However, due to the significant heterogeneity of the included reports, it is not possible to clearly determine a link between changes in salivary melatonin levels and the oncological diagnosis.

Promising applications of human-derived saliva biomarker testing in clinical diagnostics

“…230 Further, melatonin has protective, oncostatic, and antioxidant properties. 231 Salivary melatonin levels in patients with lung cancer and prostate cancer were lower compared to those in controls. 232,233 Sex hormones can also be detected in saliva.…”

Salivary Biomarkers for Alzheimer’s Disease: A Systematic Review with Meta-Analysis

“…Saliva is an easily accessible body fluid with regular alterations in composition under different pathophysiological conditions [13]. The secretion and composition of saliva might be affected by various diseases, including gastrointestinal, thyroid, oncological, autoimmune, cardiovascular, neurological and other disorders [14][15][16][17][18][19][20][21]. Also, AD may influence these qualitative and quantitative salivary parameters.…”

Melatonin ultrastructural localization in mitochondria of human salivary glands

“…For instance, in lung, prostate, breast, colon, and stomach cancer, serum levels of melatonin are decreased, while in melanoma, multiple myeloma and oral squamous cell carcinoma are increased (Salarić et al, 2021 ). Indeed, salivary and/or plasma concentration of this hormone has been suggested to represent a clinical biomarker in different tumors (Farahani et al, 2020 ; Nijakowski et al, 2022 ), thus implying its clinical importance.…”