Prostate Cancer Hormone Therapy – Combined Androgen Blockade

Prostate Cancer Hormone Therapy – Combined Androgen Blockade The use of an anti-androgen and a form of castration is called Combined Androgen Blockade or CAB. Combined androgen blockade may also be called combined hormone blockade or total hormone blockade. During prostate cancer hormone therapy, the most common form of CAB is an anti-androgen which is started a few weeks before a Luteinizing Hormone-releasing Hormone agonist. LHRH agonists by themselves will cause hormone flare which can be painful, or deadly, or both for patients with advanced prostate cancer with distant bone metastasis. The hormone flare triggered by the LHRH agonist is a reaction that causes the body to flood with testosterone for 7 to 10 days. Since testosterone can help prostate cancer grow, many patients, even those in earlier stages of less aggressive prostate cancer, may prefer to avoid hormone flare. Anti – androgens block the body’s ability to use testosterone, so the flood of testosterone never reaches the prostate gland. This form of combined androgen blockade is common for patients in later stages of prostate cancer. Hormone flare is not dangerous to early stage prostate cancer patients nor will hormone flare incite a more aggressive growth of their prostate cancer. Castration, both the surgical orchiectomy and the medical LHRH agonist and LHRH antagonist, will eliminate only 90 to 95 percent of the body’s testosterone. Some doctors may recommend that their patients opt to ablate 100% of the testosterone. Castration affects only the testosterone produced by the testicles, not the adrenal glands located near the kidneys. Taking an anti-androgen in addition to surgical or chemical castration will prevent the prostate cancer from taking up the remaining 5 to 10 percent of testosterone. Sometimes, when orchiectomy, LHRH agonists, or LHRH antagonists are no longer effective for slowing the growth of prostate cancer, the use of an anti-androgen will keep prostate cancer hormone effective for a longer period of time. The anti-androgen withdrawal effect is where the prostate cancer cells who have adapted to no testosterone are stopped by the reintroduction of testosterone. Anti-androgen withdrawal may have some effect with patients who are using combined androgen blockade. Estrogen is sometimes used with prostate cancer hormone therapies. The use of lower dose estrogen may lessen the severity or the occurrence of side effects caused by castration or anti-androgens. As a prostate cancer treatment, there is much controversy surrounding the use of combined androgen blockade (CAB). There are studies that suggest that patients who opt for combined androgen blockade as their prostate cancer treatment have slightly higher overall survival rates than those who have used castration or anti –androgens alone. These studies also indicate that combined androgen blockade has higher biochemical relapse free survival rates when compared to anti – androgens or castration alone. Other studies suggest the opposite: patients who opt for combined androgen blockade have a slightly lower overall survival rates than those who opt for castration or anti – androgens alone.