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Treatment of Breast Cancer – Hormones

​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Some forms of breast cancer use hormones (estrogen and progesterone) to grow. 

Breast cells may have "receptors" for hormones, which tell the cells to grow and become cancer.

Cancer cells may have receptors for either estrogen or progesterone. Doctors called these types of cancer cells hormone receptor positive. 

Tumors that have hormone receptors may respond to hormone therapy, which keeps cancer cells from using these natural hormones. 

This treatment could be called anti-hormone treatment, the National Cancer Institute notes.

According to​, most breast cancers are hormone receptor positive:

  • About 80% of breast cancers are estrogen-receptor positive.
  • About 65% of estrogen-receptor-positive breast cancers are also progesterone-receptor-positive.
  • About 13% of breast cancers are estrogen-receptor-positive and progesterone-receptor-negative.
  • About 2% of breast cancers are estrogen-receptor-negative and progesterone-receptor-positive.

Hormone therapy restricts or prevents the natural production of estrogen and progesterone and denies the cancer access to the hormones it needs to grow.

Your doctor can use hormone therapy at anytime during the treatment process either before or after surgery. Tumors that do not have hormone receptors will not benefit from hormone therapy.

If you are a candidate for hormone therapy, your doctor will base the course of treatment on whether you have passed through menopause or not.

Pre-menopause treatment

If you have not gone through menopause, the options include drug treatment or surgery to remove your ovaries.

The drug treatments slow or stop the growth of cancer cells that have hormone receptors. Other drugs prevent the ovaries from making estrogen.

Side effects are similar to menopause, but may be more severe. Your doctor will explain the benefits and side effects of the drug most appropriate in your situation.

Surgery to remove your ovaries stops the main source for estrogen production in your body. This brings on severe side effects similar to menopause. Only your doctor can determine if this is the best course of treatment for you.

If you are at high risk of breast cancer, but undiagnosed, your doctor may recommend the preemptive surgical removal of your ovaries before menopause.

Prophylactic ovary removal would reduce the number of new breast cancer cases among high-risk women by 50%, according to the National Cancer Institute

Post-menopause treatment

If you have already gone through menopause, surgical removal of the ovaries is not helpful since they have ceased producing as much estrogen.

However, several drug options can be helpful and your doctor will discuss the various medications.

Ongoing treatment

Hormone therapy may require taking a daily pill for up to five years. It is important that you stick to the plan regardless of how well you feel.

Breast cancer and your treatment plan take a physical and emotional toll. Don't let depression or distress interfere with your treatment plan. If the side effects of your treatment are disrupting your life, talk to your doctor about alternatives or different doses.

NOTE: Hormone therapy for breast cancer is NOT the same a hormone replacement therapy (HRT). HRT is used to ease symptoms of menopause and may be harmful if you have breast cancer.

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