The substudy will be conducted in a subsample of approximately 90 patients and will involve those Investigational Sites willing to conduct the substudy, given that they have the means for the proper and correct handling of samples. This study has an exploratory purpose, and will provide useful insight into the specific mechanisms of action of phytoestrogens as well as generate new hypotheses that can guide future research on this product. Additionally, blood equol levels will be measured to study their potential effect on treatment outcome with these isoflavones.