Background: Numerous attempts to identify active cytotoxic agents for the treatment of metastatic renal cell carcinoma (RCC) have proved disappointing. However, several recent developments in biologic therapy of neoplastic disease have substantially improved the prospects for the treatment of advanced RCC. Melatonin (MLT), a hormone regulated by the pineal gland, has been shown to act on the immune system by causing the release of cytokines from activated T-cell populations.
Methods: A series of 22 patients with documented progressing RCC entered a trial in which the authors studied the effect of a long term regimen (12 months) with human lymphoblastoid interferon (IFN), 3 mega units (MU) intramuscularly 3 times per week, and MLT, 10 mg orally every day.
Results: Twenty-one patients were evaluable for response and toxicity. There were seven remissions (33%): three complete, involving lung and soft tissue and four partial, with a median duration at the time of this writing of 16 months. Nine patients achieved stable disease, and five progressed. General toxicity was mild. Fever, chills, arthralgias, and myalgias occurred rarely. Leukopenia and hepatic enzyme elevation were modest and always reversible.
Conclusions: Response rate and toxic effects observed during this study warrant additional randomized studies to define the role of MLT's concomitant administration in the clinical response to IFN in metastatic RCC.