Men being treated for prostate cancer are commonly given GnRH (gonadotropin-releasing hormone) hormone therapy injections to block the production of testosterone. While the use of these drugs has become a routine part of prostate cancer treatment, a new Harvard study finds that the treatment increases the risk of heart attack and diabetes, and does not prolong life expectancy. The findings from this study will be published in the September 20 issue of the Journal of Clinical Oncology.
The study found that prostate cancer patients receiving a GnRH agonist had a 44 percent increased risk of diabetes, a 16 percent increased risk of coronary heart disease, an 11 percent greater risk of a heart attack, and a 16 percent increased risk of sudden cardiac death. The study collected data on 73,196 men, 66 and older, diagnosed with prostate cancer from 1992 to 1999. The researchers followed the men through 2001.
The research found that the drugs are associated with numerous unpleasant and dangerous side effects. GnRH agonists decrease bone mass, cause central obesity, and develop insulin resistance. The studyÃ¢â‚¬â„¢s author said, “We want to encourage doctors and their patients to be cautious before jumping on a potentially toxic medication.”
The use of GnRH agonists to treat prostate cancer is also known chemical castration. GnRH agonists mimic normal GnRH and occupy the pituitaryÃ¢â‚¬â„¢s gland receptors which causes the testicles to begin producing large amounts of testosterone. This increase in production is known as hormone flare or tumor flare. The GnRH agonist has a longer biological half-life than normal GnRH, so the GnRH agonist continues to occupy the receptors. The bodyÃ¢â‚¬â„¢s level of testosterone then drops to castrate level.