Recent Blog Articles

Women's Health

Another drug prevents breast cancer in postmenopausal women

August 01, 2011

A large international trial of exemestane (Aromasin), a drug that reduces the risk of breast cancer recurrence, has found that it can also help prevent breast cancer from developing in the first place. That makes exemestane a third option for preventing breast cancer in postmenopausal women who are at elevated risk for the disease. Two other drugs, tamoxifen (Nolvadex, generic) and raloxifene (Evista), are already approved for prevention, but few women take them for that purpose because they can have serious (although rare) side effects such as stroke and blood clots. Exemestane appears to have less frightening side effects — for example, hot flashes, joint pain, and loss of bone density.

All three of these drugs target estrogen, which fuels the growth of most breast cancers, but exemestane works by a different mechanism than the other two. Tamoxifen and raloxifene are selective estrogen-receptor modulators, which bind to estrogen receptors in the breast and block their interaction with estrogen. Exemestane belongs to a different class of drugs, called aromatase inhibitors, which work by blocking the body's production of estrogen. Previous studies have shown that aromatase inhibitors are more effective than tamoxifen in preventing breast cancer from recurring. The study, funded by the drug's maker, Pfizer, and conducted under the auspices of the National Cancer Institute's clinical trials unit, looked at whether exemestane could reduce the likelihood of a first occurrence of breast cancer. Results were presented at the American Society of Clinical Oncology meeting in Chicago on June 4, 2011, and simultaneously published online in The New England Journal of Medicine.

To continue reading this article, you must log in.

Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.

  • Research health conditions
  • Check your symptoms
  • Prepare for a doctor's visit or test
  • Find the best treatments and procedures for you
  • Explore options for better nutrition and exercise
Learn more about the many benefits and features of joining Harvard Health Online »

I'd like to receive access to Harvard Health Online for only $4.99 a month.

Sign Me Up

Already a member? Login ».


As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.