[Adjuvant tamoxifen duration: more large-scale randomized evidence is needed].

The Early Breast Cancer Trialists' Collaborative Group (EBCTCG) overview of worldwide evidence has demonstrated that a few years of adjuvant tamoxifen produces a moderate but definite benefit in long-term survival. However, there is major uncertainty regarding the optimal duration of tamoxifen treatment and in particular, as to whether, after a few years on tamoxifen, most women should stop or should continue for several years longer. ATLAS (Adjuvant Tamoxifen: Longer Against Shorter) is a large international randomized trial designed to assess reliably the balance of benefits and risks of prolonging tamoxifen duration by an additional five years in women who have already had some years of adjuvant tamoxifen and for whom there is uncertainty about whether to stop, or to continue for longer. It is important that most of the clinicians are aware of the uncertainties regarding the optimal duration of tamoxifen and should consider entering their patients into ATLAS, which has the potential to provide reliable evidence to answer this question that affects the management of many hundreds of thousands of women worldwide and thereby may contribute to the further downward trend in breast cancer mortality which is already being seen.