Primer on Prostate Cancer for the Newly Diagnosed Patient - Part 2
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From: J on 5 Jul 2008 09:18 Primer on Prostate Cancer for the Newly Diagnosed Patient - Part 2 http://www.bcm.edu/urology/?PMID=5080 Hormone Therapy If detected early, prostate cancer is curable. While treatment choices are still controversial, they generally are based on the stage of the disease. Surgical removal of the gland is used for early and confined tumors. Radiotherapy or small pellet radioactive implants (brachytherapy) are also used in patients with earlier stage prostate cancer or whose health makes surgery unacceptable. When the prostate cancer is advanced, spreading to other parts of the body, treatment shifts to reducing the testosterone that feeds the prostate and its tumors. By depleting it, hormone therapy reduces symptoms and prevents further growth. But while hormonal manipulation causes prostate cancer to shrink in 85 to 90 percent of advanced prostate cancer patients, it does not cure the disease. The effects only last between 24 and 36 months. Scientists believe the results are only short-lived because prostate cancer contains different genetically identical cells, some of which may respond to hormone deprivation, while others do not. It is those androgen-insensitive cells that scientists believe eventually grow, reproduce and ultimately cause death. The good news is that there is now evidence that hormonally sensitive cells may influence hormonally insensitive cells, decreasing their rate of progression. Androgen deprivation is usually achieved by either surgery or medication, in what is commonly referred to as monotherapy, because one method is used. Testosterone can be reduced by removing the testes during a bilateral orchiectomy, surgically opening the scrotum, and freeing blood vessels and nerves before cutting the glands away from surrounding tissue. The other more likely option, however, is chemical castration: injecting synthetic LH-RH agonists (blocks an action) or antagonists (stimulates an action) into the body every three months to suppress the natural production of testosterone. A second option focuses on interfering with the effects of other adrenal hormones in addition to testicular testosterone. Referred to as complete androgen blockade, or CAB, this treatment choice combines an orchiectomy or LH-RH antagonist with anti-androgens, drugs that block the effects of adrenal gland hormones by influencing a receptor in the nucleus of the prostate cancer cell. These medications include flutamide, bicalutamide and nilutamide. Some urologists add a third drug, finasteride, which blocks the conversion of testosterone to a more potent androgen, dihydrosterstosterone, or DHT. In doing so, it deprives the cancer cells of an element needed for growth. |