How Costly and Effective is Tamoxifen Compared to Arimidex?

Hormone Therapies Can Prevent Breast Cancer Recurrence

After primary treatment for estrogen-receptor-positive breast cancer, your doctor may recommend that you take hormone therapies for two to five years to prevent recurrence.  Tamoxifen and Arimidex (anastrozole) are two commonly prescribed medications for both pre- and post-menopausal women. 

Hormone Therapy & Breast Cancer Recurrence

Estrogen fuels 80% of all breast tumors, so taking medication to lower estrogen may be key to extending your survival if you are diagnosed with a hormone-sensitive cancer.

Oncologists have two classes of hormone therapy drugs to offer patients: Selective Estrogen Receptor Modulators (SERMS) like tamoxifen or aromatase Inhibitors like Arimidex. For pre-menopausal women, tamoxifen is more commonly prescribed because Arimidex may cause painful and potentially dangerous cysts in the ovaries. 

Updated Guidelines for Tamoxifen and Arimidex

The American Society of Clinical Oncology (ASCO) issued an update to their recommendations for hormone therapy for postmenopausal women; instead of using tamoxifen alone for five years after primary cancer treatments, it's now recommended that you take aromatase inhibitors after, or instead of, tamoxifen to reduce the number of tumor recurrences.

That means if you are a postmenopausal woman who was diagnosed with estrogen-receptor-positive breast cancer and been prescribed tamoxifen, you could switch to Arimidex for the remainder of your five years of hormonal therapy.

Or, your doctor may prefer that you continue your current tamoxifen course and then take Arimidex for five years after that.  

What Are the Costs and Side Effects of Tamoxifen and Arimidex?

Both types of hormone therapies may lower your levels of estrogen and help prevent a recurrence of breast cancer, but both types of medications come with some cost considerations and side effects.

Tamoxifen is the oldest and most prescribed SERM, so it is typically one of the cheapest options. But for some patients, it may cause serious side effects like blood clots, stroke or endometrial cancer. 

Arimidex (anastrozole), and other aromatase inhibitors usually cost significantly more than tamoxifen. Side effects for Arimidex include an increased risk of heart disease in women with a history of artery blockages, osteoporosis and increased cholesterol levels. 

What if Arimidex or Tamoxifen Are Too Expensive?

It is important not to skip hormone therapy if you were diagnosed with estrogen-receptor-positive breast cancer. After going through primary treatment, taking hormone therapy is like having an insurance policy against recurrence. These medications can be expensive, but there are ways to stay on therapy with cost-saving options: 

  • Health Insurance: Most private insurance providers will help cover your cost.
  • Medicare Part D: Coverage can vary depending on your location and your health plan.
  • Medicaid: Coverage varies depending on your eligibility and your state's regulations.
  • Patient Prescription Assistance Programs: Check with drug manufacturers for assistance and savings programs. 
  • State Pharmaceutical Assistance Programs: More than half of all American states have discount or assistance programs. Check to see if your state offers coverage.
  • Non-profit Organizations: Ask your doctor or clinic about local organizations that provide assistance with the cost of prescriptions.
  • Generic versions: Generic versions of Arimidex and other aromatase inhibitors are often a fraction of the cost of the brand name medication. 

Essential Tips To Consider About Hormone Therapy

Do not skip hormone therapy after you have completed primary treatments like surgery, radiation or chemotherapy for hormone-sensitive breast cancer.

Ask your doctor to prescribe generic versions of hormone therapy so you can save money. If these medications are beyond your budget, seek help with expenses through patient assistance programs or non-profit organizations

If the side effects become bothersome, tell your doctor and ask for ways to cope; there are often ways to minimize these side effects and make treatment easier. While this can be a tough process, remember that you have finished the most intense part of treatment and are moving into life after breast cancer.


American Society of Clinical Oncology Clinical Practice Guideline: Update on Adjuvant Endocrine Therapy for Women with Hormone Receptor-Positive Breast Cancer. 2010.

 Food & Drug Administration. "Arimidex Prescribing Information". Revised 2014.

Food & Drug Administration. "Tamoxifen Prescribing Information". Revised 2012. 

Experts Issue New Guidelines on Breast Cancer Drugs. Accessed 8-7-2010.

State Pharmaceutical Assistance Programs 2010. National Conference of State Legislatures. Updated: April 1, 2010.



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