Lithotripsy :: Chemotherapy :: Radiotherapy
Hormone Therapy :: Brachytherapy :: Surgery TURP
Hormonal Therapy for prostate cancer.
The progression of prostate cancer is driven by hormones and especially by Testosterone, the male hormone. It has long been recognized that “starving” the cancer by blocking it’s supply of testosterone will slow down the rate of progression (but not cure the cancer).
The production of testosterone occurs within the testicles. Regulation of testosterone levels is controlled by a hormone released from the pituitary gland within the brain. This hormone (luteinizing hormone or LH) travels in the blood stream to the testicles. Blocking the supply of testosterone to cancer cells can therefore be achieved at several levels. The initial signal from the brain can be blocked, production of testosterone by the testicles can be blocked and the receptors on prostate cancer cells to which hormones attach can be blocked.
Originally hormonal therapy was achieved by surgical removal of the testicles. Bilateral orchidectomy is a quick and relatively minor procedure that may often be done as a day case operation. It involves an incision through the scrotum and is performed under general anaesthetic. The main risks are bleeding and infection.
More recently there has been a shift towards medical hormonal therapy. The mainstay of this is an injection that blocks the LH signals coming from the pituitary gland within the brain. The medications used are known as “LHRH agonists”. There are a number of different versions however they have similar effects and side effects and are administered by an injection given at regular intervals (usually once every 3-6 months).
A second form of medical hormonal therapy blocks the hormone receptors on cancer cells directly. This group of drugs is called the “Anti-androgens” and is given as tablets on a daily basis. Although there are some small differences in side effects they are generally similar in this regard as well as in effectiveness.
There are a number of other medications which may have effects on prostate cancer, but are used less frequently and later in the treatment course. Chemotherapy has a fairly small role in prostate cancer management compared with other cancers, however is being actively investigated in a number of medical research trials.
What are the Side Effects of Hormonal Therapy?
The side effects of hormonal therapy are generally due to testosterone deprivation of normal tissues rather than because of a reaction to the medicine. There are a number of different issues seen in this situation which are grouped together as the “Androgen Deprivation Syndrome”.
Symptoms are often compared to the female menopause (which results as normal oestrogen levels decrease). They can include hot flushes, fatigue, mood swings and sexual dysfunction (loss of libido and erections). Lack of testosterone may lead to loss of muscle mass and bone density (osteoparosis) as well as weight gain. There can be growth and tenderness of the breast tissue (gynaecomastia and mastodynia). Treatment may also be associated with changes in blood cholesterol levels and possibly increase the risk of heart disease.
In an attempt to reduce the side effects of treatment, having regular breaks from therapy, “Intermittent Androgen Deprivation”, may be an option for some people.
Who is suitable for Hormonal Therapy?
Hormonal therapy in general is used in two situations. Firstly it has become an important addition to radiotherapy (although not to surgery) as it has been shown to improve it’s effectiveness. Secondly, it is used for the treatment of metastatic prostate cancer (that has spread to tissues other than the prostate). It can be a very valuable palliative (relief giving) therapy and may also prevent some of the complications of spreading disease.
Hormonal treatment works for most people for a period of time (on average several years) but may eventually lose effectiveness. The timing and risks of treatment should be personalized to the individual depending on their situation.