Aromasin May Cut Breast Cancer Return
Study Shows Switching to Aromasin After Tamoxifen Therapy Cuts Risk of Cancer Coming Back
WebMD News Archive
Dec. 15, 2006 (San Antonio) -- The breast cancer drug Aromasin cuts the risk of breastcancer recurrence by about one-third in postmenopausal women previously treated with tamoxifen, researchers report.
Only 9% of women given Aromasin -- after completing tamoxifen treatment -- suffered a recurrence, compared with 11% of those given placebo, says researcher Terry Mamounas, MD, associate professor of surgery at Northeastern Ohio Universities College of Medicine in Canton.
"Previous research showed a clear benefit for women who receive Aromasin after two to three years of tamoxifen," he tells WebMD. "The new findings show that Aromasin is also effective after five years of tamoxifen."
The study, presented at the San Antonio Breast Cancer Symposium, included nearly 1,500 postmenopausal women who after five years of taking tamoxifen were followed for the next 30 months.
How the Drugs Work
About 70% of women with breast cancer have tumors that are fueled by estrogen, making hormone therapy a cornerstone of regimens to prevent recurrences and improve survival.
For more than 25 years, doctors have been using tamoxifen (an antiestrogen) to deprive breast cancer cells of the estrogen which they need to grow. But after five years of treatment, the benefits of tamoxifen decrease.
Newer drugs known as aromatase inhibitors, such as Aromasin, block an enzyme the body uses to make estrogen, slashing the body's production of estrogen and depriving hormone-receptor-positive breast cancer cells.
Studies over the past five years have consistently shown that aromatase inhibitors shrink tumors better with fewer side effects, Mamounas says.