Extended exposure to tamoxifen in aTTom more than doubled the number of endometrial cancers (102 vs.
The dramatic findings presented in the aTTom study today will clearly have a significant impact on clinical practice on Monday and are arguably some of the most important data for the treatment of women with early-stage, hormone receptor--positive breast cancer," she said.
Cardiovascular events have not been reported for aTTOM.
A retrospective analysis of combined data from aTTom, ATLAS, and three smaller trials is planned to determine whether certain subgroups of 63 women are most likely to benefit from longer tamoxifen treatment, according to Mr.
The aTTom study randomly assigned 6,953 women with estrogen receptor--positive (40%) or ER-untested invasive breast cancer (80% estimated to be ER+) who had been taking tamoxifen for 5 years to continue tamoxifen for another 5 years or stop immediately.