A randomized placebo-controlled trial of melatonin for poor appetite in advanced cancer patients.

TPS319 Background: Although initially thought to be synthesized exclusively in the pineal gland and primarily involved as a circadian messenger of light and dark, melatonin is now recognized to have multiple actions and synthesized in various tissues including lymphocytes and the gastrointestinal tract. Melatonin supplementation stimulates appetite in animals, and its presence in the digestive tract is associated with intestinal transit and nutrient absorption. Altered levels of melatonin are found in patients with a range of cancers and preliminary nonrandomized studies in patients with advanced solid tumors suggest melatonin may attenuate weight loss, anorexia, fatigue, and depression. These studies are limited by a lack of blinding and the absence of placebo controls. Melatonin appears to be safe at doses up to 300 mg daily in noncancer patients and after prolonged use in normal volunteers. Methods: Eligibility criteria include patients with solid gastrointestinal tumors or lung cancer, a ≥ 5% involunt...