Hormone Therapy

Hormone therapy is one of the most helpful treatments for some types of cancers. These cancers grow and spread by using the body's natural hormones, like estrogen, progesterone or testosterone. Lowering the levels of these hormones or blocking their effects may help stop or slow the cancer. 

Hormone therapy is often used to treat breast cancers, prostate cancer and uterine cancer. It may be used on its own or with other treatments, like radiation therapy, to help improve results and reduce the chance of the cancer coming back.

Hormone therapy is not useful for all types of cancer. It only works for cancers that are hormone sensitive. Your health care provider will let you know if this treatment is right for you.

How does hormone therapy work?

Hormones are natural substances made by different parts of your body. They help your body work properly. Some cancers use hormones to grow. 

Hormone therapy works by either blocking your body's ability to make hormones or by keeping hormones from interacting with cancer cells.

Hormone therapy is a systemic treatment. This means the drugs travel throughout the body to block hormones wherever they’re found. It’s different from local treatments, like surgery or radiation, which only affect certain areas.

There are three main methods of hormone therapy. They are tailored to the type of cancer. Hormone therapy is often used for breast cancers and prostate cancer but can also be used for other hormone-sensitive cancers. 

Methods include:

• Blocking hormone production: Medications stop your body from making hormones that cancer cells need to grow. For instance, medications that lower estrogen levels may treat breast cancers.
• Preventing hormones from attaching to cancer cells: Drugs can block hormone receptors on cancer cells, so hormones can’t feed the cancer.
• Surgery to remove hormone-producing organs: In some cases, health care providers may recommend removing ovaries (oophorectomy) or testicles (orchiectomy) to permanently lower hormone levels. 

Types of hormone therapy

There are several types of hormone therapy, designed for specific cancers and the hormones that fuel them.

Hormone therapy for breast cancer

Therapy for breast cancer targets cancers that are fueled by estrogen or progesterone. It lowers or blocks these hormones. Common treatments include:

• Selective estrogen receptor modulators (SERMs): Medications like tamoxifen (Nolvadex) stop estrogen from attaching to cancer cells.
• Aromatase inhibitors: Drugs like letrozole (Femara) and anastrozole (Arimidex) lower estrogen levels. They are mainly used in postmenopausal women.
• Ovarian suppression: Medication or surgery to remove the ovaries stops estrogen production. It can be especially helpful for premenopausal women.
• Other estrogen receptor blockers: Drugs like fulvestrant (Faslodex) block estrogen receptors and reduce the number of receptors within the cancer cells.

These treatments help shrink tumors, prevent cancer from spreading or reduce the risk of cancer coming back after surgery.

Hormone therapy for prostate cancer

Prostate cancer is often called androgen-sensitive because it uses testosterone, a male hormone, to grow. By lowering testosterone levels, hormone therapy can reduce the size of prostate tumors and prevent the cancer from spreading. 

Common treatments include:

• Luteinizing hormone-releasing hormone (LHRH) agonists: Medications like leuprolide or goserelin (Zoladex) lower testosterone by stopping the testicles from making it. 
• Anti-androgens: Drugs like flutamide (Eulexin) or bicalutamide (Casodex) block testosterone from reaching cancer cells. This type of hormone therapy is also called androgen deprivation therapy (ADT).
• Surgical removal of the testicles: This permanently lowers testosterone levels.

How hormone therapy is used

Your health care provider may recommend different uses of hormone therapy in different ways, depending on your health and the type of cancer:

• Before surgery or radiation therapy: Hormone therapy may shrink tumors and make these other treatments work better.
• After other treatments: Using hormone therapy after radiation therapy or chemotherapy may help keep the cancer from coming back. It may also make other breast cancer treatments work better.
• As the main treatment: If you can’t have surgery or radiation because of other health conditions, hormone therapy may help.
• For advanced cancer: Hormone therapy may slow its spread and help manage your symptoms.

Side effects of hormone therapy

Hormone therapy, like other cancer treatments, can have side effects. They depend on the type of therapy and your health. Common side effects of hormone therapy include:

• Weight gain: Hormonal changes may slow your metabolism and lead to weight increases.
• Hot flashes and night sweats: Estrogen-blocking drugs and anti-androgen therapy (testosterone blocking therapy) often cause these symptoms.
• Mood changes and fatigue: Hormone fluctuations can lead to emotional shifts, depression, anxiety and lower energy levels.
• Loss of bone density (osteoporosis): Some therapies may weaken bones, making fractures more likely.

Less-common side effects include:

• Blood clots
• Changes in cholesterol levels
• Changes in parts of your body, such as enlarged or sore breasts in men receiving hormone therapy for prostate cancer
• Less interest in sex
• Loss of muscle
• Nausea or diarrhea in women receiving hormone therapy for breast cancer.

Health care providers can help manage these side effects through medications, lifestyle changes or adjusting the therapy.

Choosing hormone therapy: What to expect

Using hormone therapy depends on factors like:

• The type of cancer and whether it is hormone sensitive.
• Whether the cancer is localized or has spread.
• Other treatments being used. Hormone therapy may be combined with chemotherapy, radiation, surgery or targeted therapies to have a stronger effect.
• Your overall health. Some treatments may not be suitable if you have certain medical conditions.

Before you start hormone treatment, you may need blood tests to check your hormone levels, liver function, and overall health. 

After you start, your health care provider will monitor how well therapy is working and manage any side effects during regular follow-up visits.

Why choose Banner MD Anderson Cancer Center?

At Banner MD Anderson, our dedicated team of specialists delivers advanced, compassionate care to support you during your journey to overcome  cancer. Our tailored treatment options give you access to some of the latest hormone therapies. If you or a loved one is thinking about hormone therapy, talk to us to learn more about your options.