How You and Your Doctor Choose Your Hormonal Therapy Plan

Hormonal therapy is likely to provide you with very important benefits if you have hormone-receptor-positive breast cancer. First, your doctor will review your medical records and figure out the role of hormonal treatment for your particular situation. Next, your doctor will discuss your hormonal treatment options with you, try to get to know you and what you want, make recommendations, and help you make a decision. At different points along the way, treatment options and recommendations might change.

For all stages of hormone-receptor-positive invasive breast cancer, the aromatase inhibitors (Arimidex, Aromasin, Femara) are considered more effective than tamoxifen, with fewer serious side effects. But tamoxifen is still a very good medicine, and it remains the standard of care for pre-menopausal women.

In order to choose the right hormonal therapy for you, your doctor will consider a number of factors. Some doctors use guidelines from the American Society of Clinical Oncology (ASCO) to shape their recommendations. Your doctor will then add all the information from your personal situation, such as your type and stage of breast cancer, your menopausal status (pre- or post-), and your risk factors for recurrence. Your doctor will also consider the other types of treatment you have already had. Finally, it will be important to balance treating the breast cancer with treating any other medical conditions you might have. Another illness or condition might make it difficult for you to tolerate the possible side effects of hormonal therapy. The risks and benefits of both breast cancer and any other medical problem you have must be taken into consideration.

Menopausal status and choice of hormonal therapy

The hormonal therapy you and your doctor choose for you has a lot to do with your menopausal status.

If you are pre-menopausal, these are your hormonal therapy options:

• If you have early-stage disease, you can take tamoxifen for five years.
• You may have ovarian shutdown (using medicine) or removal (using surgery)
• After ovarian shutdown or removal, you will be post-menopausal. Your doctor might then also prescribe an aromatase inhibitor, which you would take for five years (or the remainder of the five years if you have taken already taken two to three years of tamoxifen).

If you are post-menopausal, these are your hormonal therapy options:

• If you have early-stage disease, you can take either of the aromatase inhibitors Arimidex or Femara after your initial treatment (surgery, chemotherapy, radiation).
• If you started with tamoxifen, you can switch to the aromatase inhibitor Aromasin after two or three years, and continue until you've had a total of five years of therapy.
• After five years of tamoxifen, you can take Femara for another five years (this is called "extended use therapy").
• If you have had a recurrence of disease or developed a new breast cancer that's hormone-receptor-positive while you were taking tamoxifen, you can take any of the three aromatase inhibitors (Arimidex, Aromasin, or Femara).
• If you have advanced (metastatic) disease, and you have had a recurrence while taking an aromatase inhibitor, your doctor may have you try tamoxifen or Faslodex (chemical name: fulvestrant) if you have not taken them before. Sometimes, a switch from one aromatase inhibitor to another might be recommended just in case you respond to one kind and not to another. Read more about hormonal therapy options for metastatic disease.

Type of breast disease and choice of hormonal therapy

You and your doctor will also take into consideration the type of breast disease you have when making a choice for hormonal therapy.

• Benign breast disease: If you have benign breast disease that puts you at high risk for breast cancer, tamoxifen is the only hormonal therapy currently approved by the U.S. Food and Drug Administration (FDA) for your situation.
• Ductal carcinoma in situ (DCIS): Tamoxifen is the only hormonal therapy approved by the FDA to treat women with hormone-receptor-positive ductal carcinoma in situ (DCIS). In clinical trials, aromatase inhibitors are used for post-menopausal women who have DCIS.
• HER2-positive disease: Post-menopausal women who have hormone-receptor-positive breast cancer that is also HER2-positive may be best treated by an aromatase inhibitor, rather than tamoxifen.