This is an international multicentre open study, assessing the innocuity on breast and endometrium of a 70 mg daily dose of isoflavones standardized extract (Phytosoya).~This study follows the European guidelines :one-year treatment duration, biopsy and mammography performed at the beginning and at the end of the trial, recruitment of enough subjects in order to have 300 patients with an evaluable biopsy after one year of treatment.~After 3 weeks of screening phase, the patients will be taken Phytosoya during 52 weeks. At the end of the first year of treatment, an endometrial biopsy, an endovaginal ultrasonography, a mammography, breast ultrasounds, a clinical examination and a biological assessment will be performed.~In addition, it will be proposed to patients to continue treatment during 2 additional years. At the end of the third year,the same examinations will be performed.
The main objective of this study is to determine the effects on the endometrium and breast of 70 mg daily dose of isoflavones.