A Study of the Pineal Hormone Melatonin as a Second Line Therapy in Metastatic Colorectal Cancer Resistant to Fluorouracil plus Folates

Abstract

Since there is no effective second line chemotherapy in colorectal cancer resistant to fluorouracil, this study was carried out to evaluate the therapeutic activity of the pineal hormone melatonin, which has appeared to have antineoplastic activity in some experimental conditions, in patients with metastatic colorectal carcinoma who did not respond to fluorouracil. The study included 14 patients (8 men, 6 women; mean age 58 years). Melatonin was given intramuscularly at a daily dose of 20 mg at 3.00 p.m. for 2 months; after that, melatonin therapy was continued at 10 mg/day orally in responder patients, in those with stable disease and/or an evident improvement in PS. One patient had a minor response; 3 other patients had a stable disease, wehereas the other 10 cases progressed. An evident improvement in PS was seen in 5/14 (36 %) patients. These preliminary results show that melatonin does not have important antitumor activity in metastatic colorectal cancer patients resistant to fluorouracil. However, the pineal hormone could be usefully employed as supportive care to improve the quality of life in these patients for whom no standard treatment is yet available.