Women Taking Generic Aromatase Inhibitors Are More Likely to Continue Treatment

Breast Cancer News
January 26, 2015
Erin Rowley, Writer and Content Coordinator
Reviewed By: 
Lynn Magrum, MSN, CANP

A study found that women taking low-cost, genericinfo-icon aromatase inhibitors were more likely to stick to their treatment plans than women who took more expensive, brand-name medicines. More than half of the women in this study stopped buying their aromatase inhibitors early or took them less often than recommended.

Background and Goals

Hormonal therapies, such as aromatase inhibitors, are taken daily by mouth, after surgeryinfo-icon and often chemotherapyinfo-icon, to prevent hormone receptorinfo-icon-positive, HR-positive, breast cancer from recurring, or returning. HR-positive breast cancer grows because of the hormones estrogeninfo-icon and progesteroneinfo-icon

Aromatase inhibitors can lower the risk of recurrenceinfo-icon by more than 30 percent. But every year, 7 to 10 percent of people taking these medicines stop before their doctors advise them to. These medicines are supposed to be taken for 5 or 10 years, but only 40 to 60 percent of people finish a 5-year course of treatment.

Companies that sell brand-name medicines have exclusive rights to sell them for up to seven years after a medicineinfo-icon goes on the market. After that, generic medicines, which are similar in strength and quality to the brand-name medicines, can be sold by other companies. These generics often cost much less than the name-brand medicines. Generic aromatase inhibitors became available in 2010.

It can be hard to pay for medicine, even for someone who has health insurance. To help keep costs low, many people stop buying their medicine or don’t buy as much of it as their doctor recommends. Researchers with this study wanted to see if people who bought less expensive, generic aromatase inhibitors were more likely to continue taking their medicine.


Researchers used a health insurance database to find 5,511 women who filled prescriptions for aromatase inhibitors. The women were at least 50 years old and were diagnosed with early-stage breast cancerinfo-icon in the 6 months before they filled a prescriptioninfo-icon for either a brand-name or generic aromatase inhibitorinfo-icon. All of the women had private insurance or Medicare.


The study found that most women chose to use generic medicines and that those medicines usually cost much less than brand-name medicines. It also found that women taking the less expensive, generic medicines were more likely to stick to their treatment plans.

Among women who started taking aromatase inhibitors after the generics became available,

  • 64.4 percent took generic medicines
  • 35.6 percent took brand-name medicines

Among women who started taking aromatase inhibitors before the generics were introduced, 73.2 percent switched from brand-name to generic once they were available.

The study defined co-payments, or co-pays, as the amount paid out-of-pocket for a 30-day prescription. Co-pays cost less than $15 for

  • 85.6 percent of women taking generic medicines
  • 16.3 percent of women taking brand-name medicines

More than 50 percent of women stopped treatment or didn’t buy as much medicine as recommended. Higher co-pays were linked to higher rates of stopping treatment and women taking brand-name medicines were about twice as likely to stop treatment as women taking generic medicines.

What This Means for You

The financial costs of treatment can be hard to manage, but money troubles should never stop you from getting the medicine you need. If you stop taking your aromatase inhibitor early, or you don’t take it as your doctor recommends, it could impact your risk of breast cancer recurrence.

Reach out to members of your healthcare team for help. Ask about prescribing generic medicines instead of brand-name medicines. Talk to an oncologyinfo-icon social workerinfo-icon, a professional who is trained to help people with cancer find emotional and financial resources. This person can help you get insurance or understand the insurance you have. They can also point you toward financial resources in your community.

For more information about this topic, read our Guide to Understanding Financial Concerns and look at our online resources.

Hershman, Dawn L.; Tsui, Jennifer; Meyer, Jay. The Change From Brand-Name to Generic Aromatase Inhibitors and Hormone Therapy Adherence for Early-Stage Breast CancerJournal of the National Cancer Instituteinfo-icon. Volume 106, issue 11, November 2014; doi: 10.1093/jnci/dju319.

More In Paying for Treatment

Additional Related Topics 
Hormone Receptor-Positive
Hormonal Therapy
Health Insurance