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Advanced Prostate Cancer:
Hormone Therapy

Prostate cancer is initially dependent on male hormones, or androgens, for growth.

The primary androgen is testosterone.

Hormone therapy, or androgen suppression therapy, is used for patients whose prostate cancer has spread outside the prostate or has recurred after initial treatment.

By blocking androgens, hormone therapy causes prostate cancer to shrink, or to grow more slowly. It does not ‘cure’ the cancer, but can keep it at bay, or ‘in remission’ for several years.

Hormone therapy blocks androgens from feeding the growth of prostate cancer by blocking either the production of testosterone the cancer cell’s ability to use it.

Luteinizing hormone-releasing hormone (LH-RH) agonists stop the pituitary from instructing the testes to produce testosterone. LH-RH drugs make the pituitary release all of its Luteinizing Hormone (LH), which causes a ‘flare” of increased testosterone. This causes the pituitary to stop producing LH, which then stops the testes from producing testosterone. LH-RH agonist drugs are administered by injection every three or four months.

Anti-androgens block the body’s ability to use all androgens, including those made by the adrenal glands, and can be used with LH-RH agonists to set up a total androgen blockade. They usually come in tablet form.

About 90% of men undergoing hormone therapy suffer from impotence and loss of sexual appetite. Other side effects are similar to those in women undergoing menopause, and may include hot flashes, growth of breast tissue, weight gain and reduction in muscle and bone mass.

Most prostate cancers treated with hormone therapy eventually become androgen-independent (AIPC), or hormone-refractory (HRPC). They learn to live without androgens, and begin to grow again after a median of 16-24 months, though some take longer, some a shorter amount of time. These cancers need to be treated by other methods, some of which are available through participation in clinical research.

Intermittent hormone therapy, or stopping hormone therapy whenever PSA levels return to stable low levels, is sometimes used in an attempt to prevent cells from developing resistance to treatment.

Other drugs, such as estrogen or ketoconazole, can be used and may be effective after other drugs have stopped working.

Sometimes hormone therapy is combined with surgery or radiation, either to shrink tumors in advance of treatment or to inhibit the growth of cancer cells in men with high risk of recurrence.

As most testosterone is produced in the testicles, surgical removal of the testes, or orchiectomy, is also an effective way to block hormone production. Most men prefer to use hormone blockade drugs, even though they can be more expensive, as they work just as well as surgery and the effects are reversible.