Hormone Therapy

What is hormone therapy?

Hormones are chemicals made by glands, such as the ovaries and testicles. Hormones help some types of cancer cells grow, such as breast cancer and prostate cancer. In other cases, hormones can kill cancer cells, slow their growth, or stop them from growing. Hormone therapy as a cancer treatment may be done by:

• Taking medicines that interfere with the activity of the hormone
• Taking medicines that stop the hormone from being made
• Having surgery to remove a gland that is making the hormone

Treatment Overview

How does hormone therapy work?

Your healthcare provider may advise you to have a hormone receptor test. This test is done to help learn more about the tumor and to help determine your treatment choices. This test can help to predict how the cells will react to hormones. Here is what the test results mean:

• If the test is positive: This means the hormone is probably helping the cancer cells grow. In this case, hormone therapy may be given to block the way the hormone works. It can help keep them away from the hormone receptors on cancer cells.
• If the test is negative: This means the hormone does not affect the growth of the cancer cells, and other cancer treatments may be given.

Talk about the results of the hormone receptor test with your healthcare provider.

How is hormone therapy done?

If the test shows that the hormones are affecting your cancer, the cancer may be treated in one of these ways:

• Treating cancer cells to keep them from getting the hormones they need to grow
• Treating the glands that make hormones to stop them from making hormones
• Surgery to remove glands that make the hormones. This means the ovaries that make estrogen, or the testicles that make testosterone.

The type of hormone therapy you get depends on many factors, such as

• The type and size of your tumor
• Your age
• If you have hormone receptors on the tumor
• Other factors

When is hormone therapy given?

With some cancers, people may be given hormone therapy as soon as cancer is diagnosed, and before any other treatment. It may shrink a tumor. Or it may stop the growth of the cancer.
You may have hormone therapy before or after other cancer treatments. These are called:

• Neoadjuvant treatment. This is hormone therapy done before the main cancer treatment. It helps kill cancer cells and helps boost the success of the main treatment.
• Adjuvant treatment. This is hormone therapy done after the main cancer treatment. It’s done to improve the chance of a cure.

For some cancer, such as prostate cancer, it is helpful in relieving the painful symptoms of advanced disease. The National Cancer Institute states that although hormone therapy cannot cure prostate cancer, it will usually shrink or halt the advance of disease, often for years.

Getting hormone therapy

Hormone therapy may be given in these ways:

• Pills or liquid. Many of these medicines are pills you take at home.
• Injections. Some hormone therapy medicines are given as shots. How often you get them depends on the medicine. It may be anywhere from once a month to once every 6 months.
• Surgery. In some cases, surgery is done to take out the organ or gland that makes the hormones that the cancer cells use to grow. For instance, for breast cancer, the ovaries can be taken out so they can't make estrogen. Or for prostate cancer, the testicles might be removed so they can't make testosterone.

Benefits and Risks

What are the side effects of hormone therapy?

Below are some side effects that may be linked to hormone therapy. Side effects will vary depending on the type of hormone therapy that's given. Every person's response to hormone therapy is different, and not every person will have the same side effects. Talk with your healthcare provider about the possible side effects of your hormone therapy.
Some common side effects include:

• Hot flashes
• Nausea
• Vomiting
• Bone loss (osteoporosis) and higher risk for bone fractures
• Headaches
• Mood changes
• Diarrhea
• Skin rash
• Weight gain
• A loss of desire for sex
• Fatigue
• Loss of muscle mass
• In females:
• Vaginal spotting (blood-stained discharge from the vagina that's not part of the regular menstrual cycle)
• Irregular periods
• Vaginal dryness, itching, or irritation of the skin around the vagina
• In males:
• Trouble getting an erection (erectile dysfunction)
• Breast enlargement

Side Effects

Other more serious but less common side effects include:

• In females, a higher risk of endometrial cancer (cancer of the lining of the uterus) and uterine sarcoma (cancer of the muscular wall of the uterus)
• Blood clots
• Stroke
• Eye problems, such as cataracts
• Liver toxicities