A phase II study of anastrozole plus the pineal anticancer hormone melatonin in the metastatic breast cancer women with poor clinical status

Summary The recent advances in the psychoneuroendocrinology have suggested the possibility to modulate tumor hormone dependency through a neuroendocrine approach. In particular, it has been proven that the pineal neurohormone melatonin (MLT) may stimulate estrogen receptor (ER) expression in breast cancer cells and inhibit the aromatase activity. On this basis, a study was planned to evacuate the efficacy of a concomitant treatment with the aromatase inhibitor anastrozole plus MLT in metastatic breast cancer. The study included 14 metastatic breast cancer women of poor clinical conditions with ER positive or unknown. Both anastrozole and MLT were given orally at a dose of 1 mg at noon and of 20 mg in the evening, respectively. The clinical response consisted of complete response in 2 and partial response in 6 patients. Then, an objective tumor regression was achieved in 8/14 (57%) patients, with a median dura tion of 26 months. No neoplastic cachexia occurred on treatment. This preliminary study shows that a neuroendocrine strategy with anastrozole plus the pineal hormone MLT may represent a new effective and well tolerated regimen in the treatment of metastatic breast cancer women, including those with poor clinical status, with therapeutic results apparently superior to those reported in the literature with the only aromatase inhibitor. Then, these results would justify further randomized studies of aromatase inhibitors with or without a concomitant administration of MLT, in an attempt to establish whether the pineal hormone may enhance the efficacy of the aromatase inibibitors in the treatment of human advanced breast cancer.