The 27th Annual San Antonio Breast Cancer Symposium that took place December 8-11 included the presentation of several landmark studies that may change the treatment standards for breast cancer.
New results from patient trials indicated that aromatase inhibitors are a better option than tamoxifen, the current standard therapy, to prevent recurrence in postmenopausal women with hormone-responsive breast cancer. Other studies showed that radiation therapy may not be necessary for older women, and that a simple blood test may identify women who will benefit from chemotherapy.
Aromatase inhibitors deplete circulating estrogen in postmenopausal women, shutting down an important cellular pathway needed for the development of breast cancer. Tamoxifen, in comparison, affects breast cancer by interacting with hormone receptors on the cell surface. The ATAC trial (Arimidex [anastrozole], Tamoxifen, Alone or in Combination) showed that when the aromatase inhibitor anastrozole was given instead of tamoxifen to postmenopausal women with early stage, hormone responsive breast cancer, the women were less likely to have breast cancer recurrence, had a longer period of time before recurrence, and were less likely to develop cancer in the other breast. Reports from the ABCSG 8 and ARNO 95 trials carried out in Germany and Austria showed that if the patients were already taking tamoxifen, they were less likely to have a recurrence if they switched to anastrozole after 2 years on tamoxifen, rather than remaining on tamoxifen.