At the 2012 San Antonio Breast Cancer Symposium, researchers presented the results of a collaborative international clinical trial known as ATLAS. The study, also published December 5 in The Lancet, involved more than 6,800 women with estrogen-receptor- (ER-) positive breast cancer. Women in the study took the estrogen-blocking drug tamoxifen either for the standard five years or for an extended ten years after initial surgery and/or radiation therapy.
Memorial Sloan-Kettering breast cancer specialist Clifford A. Hudis comments on the study, which found that taking tamoxifen for ten years provided additional protection against breast cancer recurrence and an improvement in overall survival. These findings could have the greatest impact on younger, premenopausal women with ER-positive breast cancer who are at a high risk of recurrence and do not have alternative treatment options after the first five years of tamoxifen therapy.