Health Encyclopedia:


Hormone Therapy for Breast Cancer

Estrogen is one of the female hormones. Some types of breast cancer cells use estrogen to grow. Hormone therapy for breast cancer is a way to reduce the action of estrogen on these cells. Read on to learn more about this treatment and what it means for you.

How the therapy works

Some types of breast cancer cells have proteins that estrogen can attach to. Estrogen can then cause these types of breast cancer cells to grow and multiply. Hormone therapy is only used on the types of cancer that have these proteins. The therapy can block the estrogen from attaching to these cells. Hormone therapy can make breast cancer less likely to recur (come back). It is the usual first-line treatment for breast cancer that has spread. It is done in addition to other treatments such as surgery, radiation, or chemotherapy. The type of hormone therapy to be used depends on factors such as your gender, your age, and whether the cancer has spread.

How the therapy is done

The therapy can be done in several ways. These include:

  • Estrogen-receptor blockers. These medications stop estrogen from working on cancer cells. They come in pill form and as an injection. They may be given for early breast cancer, or breast cancer that has spread. They may be given to reduce the risk of breast cancer in some women.

  • Aromatase inhibitors (AIs). These medications stop the body from making estrogen. Or they may stop estrogen from working in the body. They are only given to women who are past menopause. AIs come in pill form and are taken orally.

  • LHRH and GnRH agonists. These medications stop the body from making other hormones that are similar to estrogens. These hormones can also cause breast cancer cells to grow. The medications may be injected into a muscle or just under the skin. Or they may come in pill form be taken by mouth.

  • Surgery. Estrogen is mostly made in the ovaries. Surgery to remove the ovaries (ovarian ablation) may be done. This is only done in women who have not gone through menopause. It takes away the main source of estrogen in the body. This may help other hormone therapies to work better.

Possible side effects of hormone therapy for breast cancer

  • Hot flashes (sudden increase in body heat)

  • Night sweats

  • Fatigue (tiredness)

  • Reduced interest in sex

  • Vaginal dryness or discharge

  • Mood changes

  • Muscle pain

  • Joint pain

  • Nausea or vomiting

  • Weight gain

  • Headaches

Coping with side effects

Side effects vary from person to person. Some of the side effects of treatment are temporary. Others are more long-lasting. This depends on the type of medication used, and how it affects your body. Your doctor can tell you more. To help cope with side effects, try the tips below.

  • Talk to your doctor about your symptoms. He or she may prescribe medications that can help you feel better and reduce problems.

  • Avoid hot tubs, saunas, and hot showers.

  • Avoid spicy food, alcohol, and caffeine.

  • Exercise and do other physical activity.

  • Eat plenty of fruits and vegetables and fewer fatty meats and processed foods.

  • Keep mentally active.

  • Work with your partner to manage sexual changes.

  • Try counseling or support groups.

Checking your progress

During the course of your treatment, you’ll have routine visits with your doctor. You may also have tests. These allow your doctor to check your health and response to the treatment. After treatment ends, you and your doctor will discuss your treatment results. You’ll also discuss whether you need additional cancer treatments.

Risks and possible complications of hormone therapy

Risks of hormone therapy include:

  • Failure to slow the growth of cancer cells

  • Growth of other cancers

  • Blood clots

  • Stroke

  • Liver damage

  • Cataracts

  • Bone loss

  • Early menopause

  • Brittle bones and risk of fractures


For more information about cancer and its treatment, visit the websites listed below:

  • American Cancer Society,

  • National Cancer Institute,

Online Medical Reviewer: Cohen, Richard, MD
Online Medical Reviewer: Eisenberg, Seth, RN, OCN
Online Medical Reviewer: Holloway, Beth, RN, M.Ed.
Last Review Date: 8/1/2012
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