Dr. Melisko on Duration of Aromatase Inhibitor Use in Breast Cancer

Michelle E. Melisko, MD, clinical professor of medicine, University of California, San Francisco (UCSF), explains the discussion around duration of use of aromatase inhibitors (AIs) in patients who have estrogen receptor-positive breast cancer.

More than 10 years ago, it was established that continuing with an AI after tamoxifen was beneficial. MA.17R looked at the extension of an AI beyond 5 years, demonstrating an added benefit of an AI for 10 years—meeting its statistically significant endpoint.

The NSABP B-42 trial had a similar design, but these were patients who may not have had tamoxifen previously. There was a reduction in recurrences, but it did not meet the statistically significant endpoint.