Hormone Therapy for Prostate Cancer

Overview
Testosterone is the male hormone which is produced in the body mainly by the testicles, but a little bit also comes from the adrenal glands (which sit on top of the kidneys). Most prostate cancers need testosterone to grow. If testosterone is removed from the body, prostate cancer cells will die, tumors will shrink, and the PSA will drop. Testosterone can be removed in different ways. One way is to surgically remove the testicles. This however is permanent and irreversible. Another way is to give injection therapy with Lupron or Zoladex. These time released injections are given only once every one to four months and they tell the brain to tell the testicles to stop making testosterone. These medications are just as effective as testicle removal, but their effects can be reversed by stopping them. There is no advantage to surgical testicle removal over taking these injections.

There are also pills which stop testosterone's effects in the body. Two common medications are Casodex and Eulexin. These medications do not reduce the amount of testosterone. Instead, they stop testosterone from "attaching" to prostate cancer cells. Hormone therapy is often given with combinations of medications, for instance injection therapy plus pills. One powerful combination uses three different drugs: 1) Lupron or Zoladex injection, 2) Eulexin or Casodex tablets, and 3) Proscar. This is known as "triple hormone blockade" or "triple androgen deprivation (AD3)".

Hormonal therapy is often used in the following situations:

  1. Metastatic prostate cancer --which has spread to the lymph nodes or bones
  2. Recurrent prostate cancer -- which was not cured by radiation, brachytherapy or surgery
  3. Localized prostate cancer-- used temporarily along with radiation / brachytherapy to increase the cure rates for large prostate tumors
  4. Localized prostate cancer -- used instead of radiation, brachytherapy, or surgery for patients who are candidates for, but do not wish to undergo those treatments.

Problems with Hormonal Therapy
 So why isn't hormone therapy used to treat everyone with prostate cancer? Because given by itself it probably cannot cure prostate cancer. It can usually put the cancer into remission, make the tumor(s) shrink or disappear, and can lower the PSA to zero. However, some prostate cancer cells will survive the hormone therapy, and if they are not killed by other means (such as radiation) eventually these surviving cells will grow and form new tumors which do not respond to hormonal therapy. The other problem with hormone therapy is the side effects. Removing or blocking testosterone can produce several symptoms. Fortunately, these side effects are generally reversible once the hormone therapy is stopped. Side effects of "androgen deprivation syndrome" include:
  1. Hot flashes
  2. Weight gain (extra fat)
  3. Loss of sex drive
  4. Inability to get erections
  5. Some loss of muscle bulk
  6. Fatigue
  7. Thinning of the bones (osteoporosis)
  8. Anemia (reduced red blood cell count / hemoglobin)
  9. Possible memory or mood changes.
  10. Breast growth and tenderness (occurs with certain medications)

Intermittent Therapy
Once hormonal therapy is started, it is often continued for the rest of the patient's life (unless it is being combined with radiation, brachytherapy, or radical prostatectomy). However, there may be advantages to giving breaks off of the hormone therapy instead of staying on it continuously. This way, hormone therapy is given for several months, then stopped for several months, then restarted and given for several months, etc, etc. The advantages of giving hormone therapy with breaks are:

  1. During the breaks off hormone therapy, money is saved on the drugs.
  2. During the breaks, the side effects will gradually go away and quality of life will improve.
  3. By giving breaks, the cancer may respond to hormone therapy for a greater length of time before it becomes resistant. to hormone therapy. Survival time may be lengthened.

Giving hormone therapy this way is called intermittent therapy, because the hormone therapy is given intermittently, with breaks. During the breaks off hormone therapy, the testosterone levels will rise, but the PSA will also start to slowly rise. The cancer will start to slowly grow back. Once the PSA rises a certain amount, the hormone therapy is restarted. Giving the medication Proscar during the breaks will slow down how quickly the PSA rises during the break. Proscar has very few side effect. It is also sold under the name Propecia and used to help grow back hair on the scalp.

Intermittent Triple Hormone Blockade Protocol at CTCA
CTCA-Tulsa frequently uses a hormone therapy program called intermittent triple hormone blockade (ITHB). This is also known as intermittent triple androgen deprivation (IAD3). This involves using a combination of three drugs for 13 to 16 months. The combination is then stopped (as long as the PSA has dropped low enough), and Proscar is continued by itself as "maintenance" indefinitely. The PSA is checked every 3 months, and if it ever rises to 2 - 5 the combination of three drugs is restarted, and the cycle is repeated. In one study, 80% of patients were able to take a break off hormone therapy, and the average length of the break was approximately 3 years. The cycle can be repeated many times, but eventually the cancer may no longer respond to the hormone therapy. If that ever happens, other hormone medications and / or chemotherapy can be tried.


HDR brachytherapy | HDR technique | HDR vs permanent seeds | HDR monotherapy | Risk factors | Partin tables | Zeropsa protocol | Hormonal therapy | Recurrences | Natural therapies | Watchful waiting | IMRT