Hormones are substances that are found naturally in body. Sometimes when cancer develops certain hormones stimulate the cancer cells to grow. Hormone therapies stop the hormone being released or prevent it acting on the cancer cells. Hormone therapy is most commonly used to treat some breast and prostate cancers.
HORMONE THERAPHY AND BREAST CANCER
Hormone therapy will be prescribed if your breast cancer is hormone receptor positive.
In this type of breast cancer there are receptors on the cell surface that latch onto the female hormone oestrogen, which stimulates the cancer cell to grow. Oestrogen receptor positive cancers are common and account for approximately 75 per cent of breast cancers in post-menopausal women and around 50 to 60 per cent of pre-menopausal women. Testing for hormone receptors is now routinely carried out on tissue taken during a biopsy or after the operation to remove the breast cancer.
A small proportion of breast cancers (around five per cent) are sensitive to progesterone only, which may mean that they will respond to hormone therapy. In this case, your specialist will discuss the possible benefits and risks of hormone treatment with you. If your breast cancer isn't hormone sensitive (receptor negative tumours) hormone therapy will not be of benefit. If this is the case you may be offered chemotherapy only, or you may not need any further treatment.
Hormone therapy can also be used alone as a treatment for breast cancer, for example for people who have other illnesses such as lung or heart conditions that mean they are unable to have surgery or radiotherapy. It can also be an option for those who don't want to have surgery. Hormone therapy can also be used to treat breast cancer recurrences and can be used either alone or alongside other treatments, depending on what you have had before. If your breast cancer comes back when you're already being treated with hormone therapy, you'll probably be offered a different type of hormone therapy.
Types of hormone therapy
Primary (neoadjuvant) hormone therapy is given before radiotherapy (and sometimes before surgery) to reduce the size of the prostate or breast cancer. It also makes the cancer cells more sensitive to the radiotherapy so that the treatment works better.
Adjuvant hormonal therapy is given after surgery or radiotherapy to kill any remaining tumor cells, or to try and prevent the cancer from coming back. Your doctor will discuss with you if and when you need to take hormone therapy.
HORMONE THERAPHY AND PROSTATE CANCER
Hormones are substances that are found naturally in the body. Testosterone is a hormone that is mainly made by the testicles but some of it is also made in the adrenal glands found just above the
kidneys. Testosterone controls the normal growth and development of the reproductive organs. The prostate gland is part of the male reproductive system, where testosterone acts on prostate cells. If prostate cancer develops, testosterone stimulates the cancer cells to grow.
Neoadjuvant hormonal therapy is given before radiotherapy (and sometimes before surgery) to reduce the size of the prostate. It also makes the cancer cells more sensitive to the radiotherapy so that the treatment works better. Adjuvant hormonal therapy is given after surgery or radiotherapy to kill any remaining tumour cells, or to try and prevent the cancer from coming back.
Hormone therapy is also called androgen deprivation therapy (ADT). It stops testosterone from being released or prevents it acting on the prostate cells. Hormone therapy given for prostate cancer, depending on the stage of your cancer.
In this situation hormone therapy may be started as part of the planned treatment of the disease using radiotherapy to cure it. It may also be used in men who are not suitable for either surgery or radiotherapy due to their age or poor general health, but who need the disease to be controlled rather than monitored.
Cancer that has spread beyond the outer layer of the prostate to nearby tissues is known as locally advanced prostate cancer. In this case hormone therapy may be given to reduce the risk of the cancer spreading further.
Once cancer has spread to the lymph nodes and to distant tissues, such as the bones, it is called metastatic/advanced or secondary disease. Hormone therapy is the standard treatment for
prostate cancer that has spread to nearby tissues or that has developed secondary cancers or metastases.
How hormone therapy is used for prostate cancer
Hormone therapy injections or tablets can be given on their own, which is known as monotherapy. Less often, a combination of the injection and tablets may be used. This is known as combination therapy or complete androgen blockade (CAB) or maximum androgen blockade (MAB). Combination therapy prevents the stimulating action of testosterone that is made by the testicles and by the adrenal glands.
How can testosterone leveles be reduced
Most prostate cancer cells respond when testosterone is reduced. There are various ways of blocking the effects of testosterone:
1. LHRH agonist injections (pituitary-down-regulators) - LHRH stands for luteinising-hormone releasing hormone. These are drugs that reduce the levels of a hormone (luteinising hormone) made by the pituitary gland in the brain and so ‘switch off’ testosterone being made in the testicles. This injection can be given every month or once every 3 months, depending on the dose your specialist prescribes for you. The injection can be given by your GP or practice nurse. The drugs commonly used include:
- Goserelin (also called Zoladex)
- Leuprorelin (Prostap)
- Triptorelin (Decapeptyl)
- Leuprolide (Eligard).
When you begin treatment, your body actually makes more testosterone for about 2 weeks. If this happens, it is called a ‘flare’ reaction. Flare can cause more urinary symptoms or bone pain. Men treated by injection will usually be given antiandrogen tablets to stop this surge of testosterone.
These tablets are often given for 10 days before the first injection and are usually stopped after a total of about 21 days. Sometimes they may continue indefinitely (e.g. MAB), depending on your doctor's wishes.
2. Anti-androgen tablets - With anti-androgen hormone therapy, the drugs attach themselves to a receptor (a protein) on the surface of the cancer cells to prevent testosterone stimulating the cancer cells. Even the small amount that comes from the adrenal glands is blocked.
Anti-androgen therapy is usually given as tablets and is less likely to reduce sexual desire or cause impotence and hot flushes. But some men may get breast tenderness and/or enlargement
(gynaecomastia). This can be prevented by a small dose of radiotherapy to the breast tissue before starting treatment.
Examples of anti-androgen therapy include:
- Flutamide (also called Drogenil)
- Bicalutamide (Casodex)
- Cyproterone (Androcur).
3. Orchidectomy (removal of the testes) - An orchidectomy is the surgical removal of the testicles. Nearly all testosterone is made in the testicles, so removing the testicles will block the release of testosterone straight away. Usually both testicles are removed. Sometimes just the area of testicle that makes testosterone is removed through a small cut in the scrotum. This is called a subcapsular orchidectomy. If the surgeon does remove the testicles, he or she may replace them with implants to give a more realistic appearance. But with modern drugs this is now rarely used.