BREAKTHROUGH TREATMENT OF PROSTATE CANCER

Report #7210

Doctors can stop prostate cancer from spreading by giving drugs to block the male hormone, testosterone, but after a while, lack of testosterone causes prostate cancer cells to spread rapidly throughout the body.

A medical team in Italy showed that the brain hormone, melatonin, combined with Leupron, a drug to block the male hormone, testosterone, may prevent the late reaction in which lack of testosterone causes prostate cancer to spread (1). Dr. Shutsung Liao, of the University of Chicago, has shown that prostate cancer cells have little tiny hairs on their surfaces called testosterone receptors (2). When testosterone binds to these receptors, it causes the prostate cancers to grow rapidly and sometimes spread through the body. So doctors treat prostate cancer that has spread to other parts of the body with drugs to block testosterone and the cancer shrinks, but does not disappear (3). Many months later, lack of testosterone causes prostate cancer cells to spread rapidly though the body. The study from Italy shows that giving the brain hormone, melatonin, with leupron, the drug used to block testosterone, may prevent prostate cancer from spreading one or two years after testosterone has been removed. When melatonin is taken with dihidrotestosterone, it inhibits prostate cell growth (4). Melatonin is a potent antioxidant that may help to prevent prostate cancer (4), treat melanoma, a skin cancer (5), and prevent arteriosclerosis (6). Let's hope that future research supports these findings.

By Gabe Mirkin, M.D., for CBS Radio News

1) P Lissoni, M Cazzaniga, G Tancini, E Scardino, R Musci, S Barni, M Maffezzini, T Meroni, F Rocco, A Conti, G Maestroni. Reversal of clinical resistance to LHRH analogue in metastatic prostate cancer by the pineal hormone melatonin: Efficacy of LHRH analogue plus melatonin in patients progressing on LHRH analogue alone. European Urology 31: 2 (1997):178-181. Objective: Experimental and preliminary clinical studies have suggested that the pineal hormone melatonin (MLT) may stimulate hormone receptor expression on both normal and cancer cells. Moreover, MLT has appeared to inhibit the growth of some cancer cell lines. Triptorelin was injected i.m. at 3.75 mg every 28 days, and MLT was given orally at 20 mg/day in the evening every day until progression, starting 7 days prior to triptorelin. A decrease in PSA serum levels greater than 50% was obtained in 8/14 (57%) patients. Finally, a survival longer than I year was achieved in 9/14(64%) patients. This preliminary study would suggest that the concomitant administration of the pineal hormone MLT may overcome the clinical resistance to LHRH analogues and improve the clinical conditions in metastatic prostatic cancer patients. Address P Lissoni, Osped San Gerardo, Div Radioterapia, I-20052 Monza, Milano, Italy.

2) Proceedings of the National Academy of Sciences. October, 1996.

3) JF Caubet, TD Tosteson, EW Dong, EM Naylon, GW Whiting, MS Ernstoff, SD Ross. Maximum androgen blockade in advanced prostate cancer: A meta-analysis of published randomized controlled trials using nonsteroidal antiandrogens. Urology 49: 1 (JAN 1997):71-78.

4) DHT extenuates the inhibitory effects of melatonin on epithelial cell. E Gilad, H Matzkin, N Zisapel. Interplay between sex steroids and melatonin in regulation of human benign prostate epithelial cell growth. Journal of Clinical Endocrinology and Metabolism 82: 8(AUG 1997):2535-2541. Address N Zisapel, Tel Aviv Univ, George S Wise Fac Life Sci, Dept Neurobiochem, IL-69978 Tel Aviv, Israel.

5) Reiter RJ. Melatonin inhibits growth of cultured human uveal melanoma cells. Melanoma Research. February 1997, 7(1):27-31.

6) C Hu, D.N. Roberts, J.E. DN Hu/New York Eye & Ear Infirm/Dept Pathol/Tissue Culture Ctr/New York, NY 10003 USA. 6) BC reduces insulin resistance, inflammation, and hyperlipidemia, which potentiate vascular disease, the current findings further suggest that BC use in the treatment of atherosclerosis and/or restenosis deserves further investigation. Y Zhang, AH Cincotta. Inhibitory effects of bromocriptine on vascular smooth muscle cell proliferation. Atherosclerosis 133: 1 (AUG 1997):37-44. Address AH Cincotta, Ergo Sci Dev Corp, 100 1ST Ave, Charlestown, MA 02129 USA.

Reported 9/1/97; Checked 9/5/05