How Long Do You Take Hormonal Therapy?

How long you take hormonal therapy depends on your personal situation. There are different approaches for:

• adjuvant treatment (after surgery, chemotherapy, and/or radiation)
• neoadjuvant treatment (before surgery, to shrink the cancer)
• treating metastatic disease (if the cancer has spread)

After initial treatment: Adjuvant hormonal therapy

For early-stage breast cancer, hormonal therapy usually follows other forms of treatment such as surgery, chemotherapy, and/or radiation. When you have hormonal therapy after your other treatments, it is called "adjuvant hormonal therapy."

The preferred length of time for adjuvant hormonal therapy ranges from five to 10 years. If you have just finished your initial treatments and are starting adjuvant hormonal therapy, your doctor will usually prescribe tamoxifen or the aromatase inhibitor Arimidex (chemical name: anastrozole) or the aromatase inhibitor Femara (chemical name: letrozole) for the first five years.

If you have taken tamoxifen for two to three years and are now post-menopausal, your doctor might recommend that you switch over to the aromatase inhibitor Aromasin (chemical name: exemestane) for the remainder of the five years. In other words, after taking two to three years of tamoxifen, you'd take two to three years of Aromasin, for a total of five years.

If you have completed the full five years of tamoxifen, are now post-menopausal, and the cancer has not come back, your doctor may advise another five years of hormonal therapy with Femara.

For women with early-stage disease who have finished five years of any aromatase inhibitor (Arimidex, Aromasin, or Femara) it's unclear whether more hormonal therapy will be more beneficial. This important question is under study.

Before surgery: Neoadjuvant hormonal therapy

If you have a large tumor in the breast and/or significant lymph node involvement, and you have hormone-receptor-positive disease, your doctor may recommend neoadjuvant hormonal therapy. Getting hormonal therapy before surgery may shrink the cancer.

Neoadjuvant hormonal therapy may be continued for about three to six months — as long as it's working to shrink the cancer. Since the treatment is customized to your unique situation, your treatment may be the same as what's described here, or it may be longer or shorter.

To treat cancer that has spread: Metastatic hormonal therapy

For women with metastatic hormone-receptor-positive disease, hormonal therapy continues as long as it is working for you. If one hormonal therapy stops working, then another form of hormonal therapy can be tried. Usually your doctor will recommend a switch from one kind of hormonal therapy to another depending on your response.

Other considerations for length of hormonal therapy

If medical breakthroughs show that another drug is more effective for your particular type of breast cancer than the drug you are taking now, you may change from your current therapy to another one.

The length of hormonal therapy also depends on side effects. Some women have only mild side effects or can handle the side effects without difficulty. But some women have significant side effects or have trouble managing the side effects. If your quality of life isn't as good as it might be because of your current hormonal therapy, your doctor may suggest that you switch to another hormonal therapy, to see if it's easier for you to handle.

Also, you may be diagnosed with breast cancer when you're pre-menopausal, but over the course of your treatment, you may become post-menopausal. Or you might have had a hormone-receptor-negative breast cancer when you were first diagnosed but then developed a new, different breast cancer that is hormone-receptor-positive. So a medication that may not have been right for you at one time may become appropriate as your medical situation changes.

Keep reading to learn more:

• How You and Your Doctor Choose Hormonal Therapy
• Guidelines from ASCO
• Will Your Doctor Want You to Switch Therapies?
• Extended Use of Aromatase Inhibitors After Five Years