Several reports suggest that dietary soy isoflavone intake was associated with lower risk of occurrence and recurrence among postmenopausal patients with breast cancer positive for estrogen and progesterone receptor [94–96]; the development of phytoestrogen therapy for breast cancer prevention is supported by historical and regional dietary intake patterns [55–59, 80, 81] and the health benefits and the mechanisms by which these polyphenolic molecules exert their positive effects have been reviewed [97–101]. This evidence concerns the gene PGR and breast carcinoma.