AURORA, Colo. (June 20, 2012) - Prostate cancer cells require androgens including testosterone to grow. A recent review in the British Journal of Urology International describes new classes of drugs that target androgens in novel ways, providing alternatives to the traditional methods that frequently carry high side effects.
"In many ways, therapies for prostate cancer have led the way in the fight against the disease," says E. David Crawford, MD, investigator at the University of Colorado Cancer Center and review co-author. "The first effective oral therapy for any cancer was estrogen which was described in 1941. The first cancer biomarker that allowed diagnosis and staging was prostatic acid phosphatase back in 1938. Then there was little progress for over four decades."
During those 40 years, in which early work in prostate cancer led to Nobel prizes for researchers Charles Huggins and Andrew Schally, other cancer types capitalized on this research, notably developing hormone therapies targeting estrogen in breast cancer. But work in prostate cancer stalled.
"What we realized is that production of androgens like testosterone depends on an intact system in which the brain recognizes hormone levels, signals the pituitary to increase or decrease production, and the pituitary in turn sets the testes in motion. Additionally, by targeting the production of androgens by the testes, we could break that system at many other points," Crawford says.
For example, estrogen is similar enough to testosterone that administering estrogen to patients tricked the brain into thinking testosterone hormone levels were high with high presumed hormone levels, the brain sent no production signal to the pituitary. But estrogen therapy led to side effects including breast enlargement.
The next class of drugs, known as luteinizing hormone releasing hormones or LHRHs, intervened in this signaling chain at the level of the pituitary. Just as estrogen keeps th
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University of Colorado Denver