Hormonal therapy is a treatment that adds, blocks or removes hormones to slow or stop the growth of cancer cells that need hormones to grow. Hormonal therapy is also called hormone withdrawal therapy, hormone manipulation or endocrine therapy.
Hormonal therapy may be used alone as the main treatment or with other treatments. It may be used before surgery to shrink the tumour and make it easier to remove or before radiation therapy to shrink the tumour so radiation can be given to a smaller area. Hormonal therapy may be given in addition to main treatments such as surgery, radiation therapy or chemotherapy to lower the risk that the cancer will come back (recur).
Hormones are chemicals that travel in the blood and control how some cells and organs act and grow. Natural hormones are produced by glands or organs in the body. Artificial or synthetic hormones can be made in a lab.
The ovaries produce the female hormones estrogen and progesterone, which are involved in reproduction.
The testicles produce the male hormone testosterone, which is involved in reproduction.
The pituitary gland produces:
- luteinizing hormone (LH), which stimulates the testicles and ovaries
- adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands
- follicle-stimulating hormone (FSH), which stimulates the ovaries and testicles
- thyroid-stimulating hormone (TSH), which stimulates the thyroid gland
The adrenal glands produce:
- glucocorticoids, which lower the body’s immune response
- mineralocorticoids, which help maintain the water and electrolyte balance in the body
- estrogen, in small amounts, in post-menopausal women
- testosterone in men, in small amounts, which is involved in reproduction
The pancreas produces glucagon, which raises the blood sugar level, and insulin, which lowers the blood sugar level.
How hormonal therapy works
Hormonal therapy changes hormone levels in the body. Hormone levels can be changed by:
- removing the gland or organ that makes the hormone
- giving radiation to the gland or organ to destroy hormone-producing cells
- taking hormones or other drugs that interfere with or stop (suppress) the production of the hormone (called hormonal drug therapy)
Types of hormonal therapy
There are several types of hormonal therapy that change the levels of hormones in the body. Hormonal therapy is usually given along with other treatments. The type of hormonal therapy used depends on a number of factors including which type of cancer you have.
Surgery removes glands or organs to stop them from producing hormones or to work against a hormone in the body.
Radiation therapy destroys or damages hormone-producing tissue to stop hormone production.
Hormonal drug therapy
Some drugs interfere with hormone-producing cells so they can’t make hormones. Other drugs work against a hormone or a hormone’s effects in the body. Hormone-dependent cancer cells have receptors on their surfaces. Receptors are sites where the hormones attach to the cancer cells and tell them to grow.
A sample of the tumour may be tested to find out the type of hormone receptor on the surface of the cancer cells and the amount of receptor (hormone receptor level). Generally, the higher the hormone receptor level, the more responsive the tumour will be to hormonal drug therapy.
Corticosteroid (steroid) hormones are used to treat cancers such as lymphoma, leukemia and multiple myeloma. They are often combined with chemotherapy drugs to increase their effectiveness. Prednisone, dexamethasone (Decadron, Dexasone), hydrocortisone and methylprednisone (Medrol) are types of corticosteroid drugs.
Thyroid hormones stop the growth of thyroid tumours after surgery or radiation therapy for thyroid cancer. They are also used to replace thyroid hormones in the body when the thyroid gland is removed. Levothyroxine (Synthroid, Eltroxin) is a thyroid hormone drug.
Somatostatin analogues are drugs that lower the number of hormones made and released by neuroendocrine tumours (NETs). They are mainly used to control symptoms of carcinoid syndrome. Octreotide (Sandostatin, Sandostatin LAR) is a somatostatin analogue.
Sex (reproductive) hormones are used to treat cancers that need male or female hormones to grow.
- Androgen is a male hormone and is used to treat breast cancer. Fluoxymesterone (Halotestin) is an androgen drug.
- Estrogen is a female hormone and may be used to treat metastatic prostate cancer and metastatic breast cancer. Diethylstilbestrol (DES) is an estrogen drug.
Progestin is a female hormone. It is used to treat breast cancer and sometimes uterine (endometrial) cancer and prostate cancer. Medroxyprogesterone (Provera) and megestrol (Megace) are types of progestin drugs.
Anti-androgens are used to treat prostate cancer. Bicalutamide (Casodex), flutamide (Euflex) and nilutamide (Anandron) are types of anti-androgen drugs.
- Anti-estrogens include estrogen blockers and selective estrogen receptor modulators (SERMs). They are used to treat breast cancer, uterine cancer and ovarian cancer. Fulvestrant (Faslodex) and tamoxifen (Nolvadex, Tamofen) are types of anti-estrogen drugs.
- Aromatase inhibitors are used to treat breast cancer and ovarian cancer in woman who have gone through menopause. Anastrozole (Arimidex), exemestane (Aromasin) and letrozole (Femara) are types of aromatase inhibitor drugs.
- Luteinizing hormone–releasing hormone (LHRH) agonists are also called gonadotropin-releasing hormone (GnRH) analogues. They are used to treat prostate cancer and breast cancer. Buserelin (Suprefact), goserelin (Zoladex) and leuprolide (Lupron, Lupron Depot, Eligard) are types of LHRH agonist drugs.
- Gonadotropin-releasing hormone (GnRH) antagonists are used to treat prostate cancer. Degarelix (Firmagon) is a GnRH antagonist.
For more detailed information on specific drugs, go to sources of drug information.
Getting hormonal therapy
Your healthcare team will explain exactly how you will get hormonal therapy. Hormone receptor tests may be done to see how well your cancer will respond to hormonal therapy and if it will be helpful as part of your treatment.
Preparation for hormonal therapy depends on the type of treatment chosen. Some special preparations may be needed before surgery or radiation therapy. There is no preparation needed for hormonal drug therapy.
Surgery can be used to remove hormone-producing glands or organs.
- Removing the ovaries (called an oophorectomy) lowers the level of estrogen in the body and may be used to treat breast cancer.
- Removing the testicles (called an orchiectomy) lowers the level of testosterone in the body and may be used to treat prostate cancer.
In radiation therapy, radiation is aimed at hormone-producing glands or organs to destroy the cells that produce hormones. For example, radiation can be directed at the ovaries to stop them from producing estrogen. It is usually given as external beam radiation therapy.
Hormonal drug therapy
Drugs are commonly used to stop hormone production. The type of hormonal drug therapy and the length of treatment will depend on the type of cancer and your response to treatment. The drugs may be used for a specific length of time or for as long as the cancer responds to the treatment. Combinations of hormonal therapy drugs may be used in some situations. Hormonal drug therapy is given by mouth or injection.
After hormonal therapy
Recovery during and after hormonal therapy depends on:
- the type of hormonal therapy used
- your general health and how well you tolerated the therapy
- the side effects you experienced
The healthcare team will give you instructions if there are special precautions you need to take after hormonal therapy.
Follow-up appointments are usually scheduled:
- to see how the cancer is responding to hormonal therapy
- to see how you are tolerating hormonal drug therapy
- to discuss ways of lessening and treating side effects
One of a pair of small, round organs in the pelvis of females (on each side of the uterus, or womb) that produce germ cells (eggs) and the female sex hormones.
Ovarian means referring to or having to do with the ovaries, as in ovarian cancer.
One of a pair of small, egg-shaped organs inside the scrotum (the pouch of skin below the penis) that produce sperm and the male sex hormones.
Testicular means referring to or having to do with the testicles, as in testicular cancer.
Also called testis or testes (plural).
The main endocrine system gland at the base of the brain that produces hormones to control other glands and many body functions, including growth.
Also called the hypophysis.
A small gland on top of each kidney that produces a variety of hormones involved in different body functions, including metabolism (the chemical processes needed for cell function, growth and reproduction), heart rate, blood pressure and controlling blood sugar levels.
The long, tapered organ behind the stomach that makes digestive juices and passes them into the duodenum (the first part of the small intestine) through the pancreatic duct. It also makes hormones (such as insulin) that help to regulate how the body stores and uses food.
Pancreaticmeans referring to or having to do with the pancreas, as in pancreatic cancer.
What’s the lifetime risk of getting cancer?
The latest Canadian Cancer Statistics report shows about half of Canadians are expected to be diagnosed with cancer in their lifetime.