Early Breast Cancer TreatmentHormonal breast cancer treatment basics

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If my breast cancer is gone, why do I need hormonal treatment?

Adjuvant hormonal treatment following surgery and/or radiation therapy is a way of helping to reduce the risk of breast cancer coming back. Cancer cells too small to be detected can break away from the initial tumor and travel throughout the body. The initial tumor is removed through surgery, but those small cells that remain can result in recurrence.

Hormones can make cancer cells grow and multiply. Therefore the cells that remain after initial surgery and radiation can grow to a detectable size. Hormonal therapies can decrease or block production of hormones from reaching breast cancer cells. In early breast cancer, hormonal treatment has been shown to help reduce the risk of breast cancer coming back (recurrence). Below is some information that can help you understand how hormonal breast cancer treatment works.

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Understanding the role of hormone receptors

Some breast cancer tumors need certain natural hormones to grow. These have receptors for the hormones estrogen and/or progesterone.

  • Hormone receptors are very small parts of a cell. If estrogen is present, it will attach to estrogen receptors, possibly making the tumor grow larger
  • Tumors with hormone receptors are called estrogen and/or progesterone receptor positive, or hormone receptor positive
  • Results of the biopsy of your cancer give your medical team information about whether your cancer is hormone receptor positive
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How hormonal treatment for breast cancer works

Different types of hormonal breast cancer treatments work in different ways.

  • Drugs called antiestrogens are a type of hormonal treatment that works by blocking estrogen receptors. In other words, these drugs interfere with breast cancer growth by attaching to estrogen receptors in breast cancer cells. This means estrogen itself cannot attach to cancer cells. So even though estrogen is present, its activity is blocked. The most common antiestrogen is tamoxifen
  • Drugs called aromatase inhibitors reduce the action of aromatase, an enzyme needed to make the hormone estrogen. ARIMIDEX is an aromatase inhibitor. It lowers the amount of estrogen produced in the body

Although there are different types of hormonal breast cancer treatment, hormonal treatment should not be confused with other treatments.

  • Hormonal treatment is not the same as cytotoxic chemotherapy. Cytotoxic (cell-killing) chemotherapy can kill both cancer cells and some other healthy cells in the body. Hormonal treatment works by blocking the effect of estrogen or lowering the amount of estrogen in the body
  • Hormonal breast cancer treatment is not the same as hormone replacement therapy (HRT). Hormonal treatment is used to block the effect of estrogen or reduce estrogen levels. The goal is to keep estrogen from reaching cancer cells and stimulating cell growth. HRT, however, supplies estrogen to menopausal women to help ease the signs and symptoms of menopause
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Sticking to your breast cancer treatment plan

Taking your medication as prescribed is important.

Here are some tips to help you remember to take your hormonal treatment.

  • Take it at the same time every day, along with breakfast, for example, or when you brush your teeth in the morning
  • Use special pillboxes that help you keep track of your medication schedule. These pillboxes are sometimes divided into days of the week and can be found at any drugstore
  • Ask people who are close to you to remind you to take your medicine
  • Keep a "medicine calendar" and make a note every time you take your dose
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Important Information About ARIMIDEX

ARIMIDEX is approved for adjuvant treatment (treatment following surgery with or without radiation) of postmenopausal women with hormone receptor-positive early breast cancer.

ARIMIDEX is approved for the initial treatment of postmenopausal women with hormone receptor-positive or hormone receptor-unknown locally advanced or metastatic breast cancer and for the treatment of postmenopausal women with advanced breast cancer that has progressed following treatment with tamoxifen. Patients with hormone receptor-negative disease and patients who did not previously respond to tamoxifen therapy rarely responded to ARIMIDEX.

Important Safety Information About ARIMIDEX

  • Prescription ARIMIDEX is only for postmenopausal women. ARIMIDEX should not be taken if you are pregnant because it may harm your unborn child
  • Based on information from a study in patients with early breast cancer, women with a history of blockages in heart arteries (ischemic heart disease) who take ARIMIDEX may have a slight increase in this type of heart disease compared to similar patients who take tamoxifen
  • ARIMIDEX can cause bone softening/weakening (osteoporosis) increasing the chance of fractures. In a clinical study in early breast cancer, there were more fractures (including fractures of the spine, hip, and wrist) with ARIMIDEX (10%) than with tamoxifen (7%)
  • In a clinical study in early breast cancer, some patients taking ARIMIDEX had an increase in cholesterol. Skin reactions, allergic reactions, and changes in blood tests of liver function have also been reported
  • In the early breast cancer clinical trial, the most common side effects seen with ARIMIDEX include hot flashes, joint symptoms (including arthritis and arthralgia), weakness, mood changes, pain, back pain, sore throat, nausea and vomiting, rash, depression, high blood pressure, osteoporosis, fractures, swelling of arms/legs, insomnia, and headache
  • In advanced breast cancer trials, the most common side effects seen with ARIMIDEX versus tamoxifen include hot flashes, nausea, decreased energy and weakness, pain, back pain, headache, bone pain, increased cough, shortness of breath, sore throat, and swelling of arms and legs. Joint pain/stiffness has been reported in association with the use of ARIMIDEX
  • ARIMIDEX should not be taken with tamoxifen or estrogen-containing therapies

Please click here for full Prescribing Information.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.FDA.gov/medwatch or call 1-800-FDA-1088 (1-800-332-1088).