Hormone Therapy

Hormone therapy, also called hormonal therapy or endocrine therapy, is a cancer treatment that slows or stops the growth of cancer that relies on hormones to grow.

Hormones are chemical messengers that affect and manage hundreds of processes in the body. While they are essential for life and health, they can also cause certain types of cancer to grow and spread. Among these are cancer of the breast, ovary, prostate and uterus.

Hormone therapy may help slow or stop cancer from growing, particularly if it’s combined with other treatments.

Hormone therapy uses drugs to block or alter hormones to help slow or stop the growth of certain types of cancer. It is used primarily to treat certain kinds of breast cancer and prostate cancer that rely on sex hormones (estrogen, progesterone and testosterone) to grow.

Hormone therapy is a systemic treatment that circulates throughout the body. It is typically given by pill, capsule, liquid or injection. The medicines used in hormone therapy travel in the body to find and target the specific hormones. Different types of hormone therapy work in different ways:

• Some treatments block the hormone receptors on your cancer cells, which prevents the cancer from using the hormones.
• Surgery removes the organ that makes the hormone that fuels your tumor. For example, removing a woman’s ovaries before menopause eliminates the main source of estrogen.
• Certain medicines can prevent your body from making particular hormones. For example, men with prostate cancer may take medication that reduces their testosterone level to nearly zero.

Who can have hormone therapy?

If your cancer is hormone-sensitive, hormone therapy may be a treatment you receive. Once your doctor has confirmed you have hormone-sensitive cancer, he/she may recommend treatment with hormone therapy. Hormone therapy can also cause side effects, so your doctor will consider your overall health when recommending the best cancer treatment for you.

Hormone therapy is most often used along with other cancer treatments. The types of cancer treatment that you may need will depend on your type of cancer, if it has spread and how far, if it relies on hormones to grow and if you have other health concerns.

How is hormone therapy delivered?

If your doctor determines that hormone therapy is appropriate for you, there are several ways you may receive it: orally, by pill, capsule or liquid; by intramuscular or subcutaneous injection; or through surgery to remove the hormone-making organ(s).

Many types of hormone therapy can be taken by mouth and at home. How often you take your hormone treatment depends on the drug you’re receiving and the type of cancer you have. It’s important to follow instructions exactly when taking your hormone therapy. Depending on the drug you’ve been prescribed, there may be special precautions to take.

Some types of hormone therapy are given by injection in the arm, leg or hip, and others are given just under the skin of the abdomen. How often you receive these injections depends on the drug and the type of cancer you have. You may receive the injections at your cancer treatment center or doctor’s office. In some instances, patients and/or their caregivers are taught to give the injections.

Some types of surgery are also forms of hormone therapy. For example, an oophorectomy (surgery to remove the ovaries, the body’s main source of estrogen and progesterone) can be an option for some women with breast cancer. Side effects from this type of hormone therapy are similar to those from medicines that lower hormone levels in the body.

Like most cancer treatments, hormone therapy may cause side effects. Everyone’s experience is different. Your reaction to hormone therapy depends on your overall health and the kind of hormone therapy you receive. Your doctor and your cancer care team will talk with you about potential side effects.

What are the side effects of hormone therapy?

Not everyone who receives hormone therapy will experience side effects. If you do experience side effects, they may be different from side effects someone else experiences. When determining your particular cancer treatment, your doctor and your cancer care team will discuss with you the potential side effects of hormone therapy. It’s important to balance the benefits and risks of any cancer treatment.

Potential side effects of hormone therapy may include:

For men receiving treatment for prostate cancer:

• Hot flashes
• Decreased sexual desire
• Erectile dysfunction
• Bone loss and a higher risk for fractures
• Fatigue
• Weight gain with decreased muscle mass
• Memory problems
• Increased risk of other health problems

For women receiving treatment for breast or endometrial cancer:

• Hot flashes
• Vaginal discharge, dryness or irritation
• Decreased sexual desire
• Fatigue
• Nausea
• Pain in muscles and joints
• Bone loss and a higher risk for fractures
• Higher risk of other types of cancer, stroke, blood clots, cataracts and heart disease

Men receiving treatment for breast cancer experience many of the same side effects as women, along with erectile dysfunction.

How long does hormone therapy last?

You may receive hormone therapy for weeks, months or years, depending on the type of cancer you have and the kind of hormone therapy you are prescribed. Your doctor and your cancer care team will determine how long you should receive hormone therapy.

How can my doctor tell if hormone therapy is working?

If you are taking hormone therapy for prostate cancer, you will have regular PSA tests. If hormone therapy is working, your PSA levels will stay the same or may even go down. But, if your PSA levels go up, it may indicate that the treatment is no longer working. If this happens, your doctor will discuss treatment options with you.

If you are taking hormone therapy for breast cancer, you will likely have regular check-ups to examine your neck, underarm, chest and breast areas. Depending on whether you had a lumpectomy or mastectomy or mastectomy with reconstruction, you may have regular mammograms. Your doctor may also order other imaging procedures or laboratory tests.