Authors: Egidio Del Fabbro, Rony Dev, David Hui, Lynn Palmer and Eduardo Bruera
Journal of Clinical Oncology 2013
Melatonin, produced in the pineal gland of the brain, is part of the system that controls the sleep-wake cycle. It is sold in the United States as a dietary supplement and is most commonly used for the treatment of sleep disturbances, such as jet-lag. Melatonin is also a potent antioxidant and has been shown in animal studies to prevent DNA damage by cancer causing toxins. Multiple studies have suggested that melatonin may also decrease weight loss, loss of appetite, and fatigue in patients with cancer. These symptoms are some of the most problematic for patients dealing with advanced cancer and cancer therapy.
A clinical trial was conducted to validate the effects on appetite and fatigue using a randomized, placebo controlled study design. Patients with advanced lung or GI cancer, a loss of appetite as determined by an “appetite score”, and a loss of weight over the past 6 months were eligible to enroll in the study. Patients were randomized to receive either melatonin at 20 mg each night or a placebo. Neither the patient nor the physician were aware of which treatment the patient was receiving. A number of symptoms related to appetite and fatigue were tracked over the 28 day course of the study. Patients were also monitored for weight changes and changes in body composition such as body fat and lean mass.
Seventy three patients were eligible and assigned to receive either melatonin or the placebo. All patients completed questionnaires to evaluate their symptoms related to appetite, fatigue, depression, pain and well-being, prior to starting their assigned therapy and after 4 weeks of therapy. All patients underwent evaluation of body fat and lean body mass prior to starting therapy and after 4 weeks of therapy. No difference in symptoms or body composition was detectable between the two groups. Melatonin was not effective for improving appetite or other symptoms and did not improve quality of life in patients with advanced cancer. This is the first study to evaluate the effects of melatonin using a rigorous study design and does not support the recommendation of melatonin for the treatment of fatigue or weight loss.