Melatonin, a Prognostic Marker in Oncologic Pathology

D. Mihu, N. Costin, R. Ciortea, C. Georgescu, V. M. C. , D. M. Groza,

Abstract: Melatonin is the major secretion product of the pineal gland. The main function of melatonin is to control the sleep-wake mechanism and the circadian rhythm. Pineal secretion follows a circadian rhythm with low levels during the day and high levels at night. In people who work in night shifts, melatonin suppression following nocturnal exposure to artificial light alters the inhibition of ovarian estrogen secretion resulting in high estrogen levels, directly linked with the incidence of breast and endometrial cancer. Melatonin also plays a role in neuroendocrine regulation, in boosting immunity, in neutralizing free radicals, in reducing angiogenesis and in increasing apoptosis. Over the past years, studies on animals and humans have demonstrated that melatonin has important oncostatic effects. Blood melatonin levels are reversely correlated with the tumor proliferation index in patients with breast, endometrial and ovarian cancer. All this evidence supports the idea that melatonin levels can be a useful biochemical marker in the prevention, the diagnosis, the treatment monitoring and the prognosis of various types of cancer.
Keywords: melatonin, cancer, oncostatic effect, apoptosis, angiogenesis.