Cancer immunotherapy with low-dose interleukin-2 subcutaneous administration: potential efficacy in most solid tumor histotypes by a concomitant treatment with the pineal hormone melatonin.

The antitumor efficacy of IL-2 is limited to renal cancer and melanoma. Several cytokines have been associated with IL-2 in an attempt to improve its activity, without, however, any clear benefit. Recent experimental and clinical studies have suggested the possibility to manipulate the host biological response by immunomodulating neurohormones, such as the pineal hormone melatonin (MLT).