TREATMENT OF CANCER CHEMOTHERAPY-INDUCED TOXICITY WITH THE PINEAL HORMONE MELATONIN

Experimental data have suggested that the pineal hormone melatonin (ML T) may counteract chemotherapy-induced myelosuppression and immunosupp ression. In addition, MLT has been shown to inhibit the production of free radicals, which play a part in mediating the toxicity of chemothe rapy. A study was therefore performed in an attempt to evaluate the in fluence of MLT on chemotherapy toxicity. The study involved 80 patient s with metastatic solid tumors who were in poor clinical condition (lu ng cancer: 35; breast cancer: 31; gastrointestinal tract tumors: 14). Lung cancer patients were treated with cisplatin and etoposide, breast cancer patients with mitoxantrone, and gastrointestinal tract tumor p atients with 5-fluorouracil plus folates. Patients were randomised to receive chemotherapy alone or chemotherapy plus MLT (20 mg/day p.o. in the evening). Thrombocytopenia was significantly less frequent patien ts concomitantly treated with MLT. Malaise and asthenia were also sign ificantly less frequent in patients receiving MLT. Finally, stomatitis and neuropathy were less frequent in the MLT group, albeit without st atistically significant differences. Alopecia and vomiting were not in fluenced by MLT. This pilot study seems to suggest that the concomitan t administration of the pineal hormone MLT during chemotherapy may pre vent some chemotherapy-induced side-effects, particularly myelosuppres sion and neuropathy. Evaluation of the impact of MLT on chemotherapy e fficacy will be the aim of future clinical investigations.