In a joint analysis of two clinical trials reported at the American Society of Clinical Oncologists meeting in Chicago, researchers found that premenopausal women who received ovarian suppression (a treatment that temporarily puts premenopausal women into menopause) and who were treated with Aromasin® (exemestane) reduced breast cancer recurrence relative to those treated with tamoxifen. There was not, however, a difference in overall survival after 68 months of follow-up.
The growth of one type of breast cancer, HR positive (HR+) breast cancer, is, in part, fueled by the hormone estrogen. In some patients monthly injections are used to suppress the functioning of the ovaries, which results in dramatic decline in estrogen levels. This treatment is thought to slow or stop tumor growth.
The TEXT and SOFT clinical trials enrolled 4,690 patients with early HR+ breast cancer who had undergone some form of ovary (estrogen) suppression. The patients were then randomized to treatment with Aromasin or tamoxifen.
After a 5-year course of treatment, the Aromasin group was significantly less likely to have a recurrence of cancer than the tamoxifen group. The difference in recurrence rates was a little less than 4 percent. Both groups had comparable overall survival after 68 months of follow-up.
The two arms of the study also had comparable rates of adverse events due to treatment, 30.6 percent for the Aromasin group and 29.4 percent for the tamoxifen patients. Similarly, quality of life assessments for the two treatments did not favor either group. It is thought that little difference was seen in quality of life because ovarian suppression was given to both groups, and this approach likely had the most dramatic effect on quality of life.
The researchers concluded that Aromasin plus ovary suppression provides a viable new treatment for premenopausal women with HR+ breast cancer.
Reference: Pagani O, et al. Adjuvant exemestane with ovarian suppression in premenopausal breast cancer. N Engl J Med 2014; DOI: 10.1056/NEMJoa1404037.
Posted June 13, 2014