Breast Cancer Action Urges Caution Regarding Aromasin for Prevention

For immediate release

Contact: Angela Wall, Communications Manager (415) 243-9301, x.16

SAN FRANCISCO, CA—Breast Cancer Action (BCAction) called for caution today about the implications of a recently published study exploring the use of the drug Aromasin (exemestane), an aromatase inhibitor (AI), in healthy postmenopausal women to reduce the risk of invasive breast cancer.

The study, led by Canada’s NCIC Clinical Trials Group, presented at the American Society of Clinical Oncology’s conference on June 4, 2011 and financed in part by the pharmaceutical giant Pfizer, examined the use of an aromatase inhibitor for reducing women’s risk of breast cancer. The study showed that women taking Aromasin developed breast cancer at a lower rate than those taking the placebo.

BCAction expressed concern about the tendency to expand approved breast cancer treatment drugs into broader markets, including prevention, without the necessary rigor to determine which women would actually benefit from the drug. In this study, women were considered at high risk of developing breast cancer if they had identified risk factors or were at least 60 years old.

“When exploring ‘preventive’ treatment for breast cancer in healthy women, the bar needs to be especially high,” BCAction Executive Director Karuna R. Jaggar said. “Without a rigorous definition of “high risk”, this study opens the door to exposing thousands and thousands of healthy women who will never get breast cancer to the side effects of a powerful drug.”

Specifically, BCAction expressed concern about this study’s broad categorization of women as high risk for breast cancer based solely on being age 60 years or older, noting that this could open the door to treating all women over 60 with an aromatase inhibitor.

BCAction reiterated its opposition to “pills for prevention,” due partly to a lack of information about the long-term effects on healthy women taking drugs like Aromasin.  Study sizes are too small, and follow-up too short, to reveal rarely occurring adverse outcomes or to assess the possibility that risks continue to develop after cessation of treatment.

“While every person diagnosed with breast cancer is one too many, this study shows you would have to treat 94 healthy women for several years with a powerful drug in order to prevent one case of breast cancer,” Jaggar said. “In addition, we don’t know what the long term effects of taking this drug will be on these healthy women.”

BCAction remains committed to primary prevention of breast cancer, which necessitates directing resources and funding to determining and eliminating the root causes of breast cancer, including environmental triggers.

“This drug is a huge moneymaker for any company and we believe it is the wrong path to take,” Jaggar said. “We believe these resources should be better spent on primary prevention including finding the disease’s environmental triggers.”

Breast Cancer Action ( is a national watchdog and advocacy organization that carries the voices of people affected by breast cancer to inspire and compel the changes necessary to end the breast cancer epidemic.


Since 1998, BCA has refused to accept funds from corporations that may create a real or apparent conflict of interest for BCAction. Corporations covered by this policy include pharmaceutical companies.

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