NEW YORK--Finasteride (Pros-car), currently FDA approved for use
in patients with symptomatic benign prostatic hyperplasia (BPH),
is also being investigated as a prostate cancer treatment and
is showing promise as an agent to prevent prostate cancer by reducing
levels of dihydrotestosterone (DHT), Glenn J. Gormley, MD, PhD,
said at the first International Conference on Cancer Prevention.
The program was sponsored by Strang Cancer Prevention Center,
Cornell University Medical College, and the European School of
Dr. Gormley, senior director of clinical research, endocrinology
and metabolism, Merck Research Laboratories, was one of the key
individuals involved in the introduction of the compound.
He told the audience that a combined National Cancer Institute
and Southwest Oncology Group clinical trial is now underway to
assess the efficacy and safety of finasteride as a prostate cancer
preventive. It will be given over a period of about 7 years to
some 18,000 men aged 55 to 70 years who have no existing prostate
Finasteride inhibits 5-alpha-reductase, thereby blocking the conversion
of testosterone to the more potent androgen DHT, Dr. Gormley said.
"DHT has five to 10 times the affinity for the androgen receptor."
He also stressed that "with the 5-alpha-reductase inhibitors,
you can remove DHT-mediated functions without interfering with
testosterone-mediated ing functions of the body."
This is a very important point in understanding the safety profile
of finasteride and how it differs from that of the antiandrogens,
which block the binding of all androgens within the cells and
produce more of the "castration-like" effect, he said.