We don't have confirmation of that yet for women taking tamoxifen for prevention for five years. There are studies that are continuing in the prevention arena, such as the European studies. We don't know all the molecular answers to those questions. One of the criticisms of BCPT was that perhaps we were treating early breast cancer that already existed. But we don't know all the answers about the physiology and pathology from a healthy breast to a diseased one.
Cancer takes a long time to develop.
The Breast Cancer Prevention Trial was stopped early because the researchers felt that tamoxifen should not be withheld from the placebo group. STAR does not have a placebo group. As for the logic behind not having a placebo group in STAR, in my mind this is very clear. It's not ethical. Tamoxifen and raloxifene have side effects.