Modulation of Growth and Differential in Breast Cancer by Soy Isoflavones

Our studies investigate the in vivo effects of soy isoflavones on human breast tissues obtained from lumpectomymastectomy specimens. We investigate the effect of increased tissue concentration of isoflavones for a period of three weeks on breast cell proliferation, differentiation and cell cycle regulatory proteins. Patients with ductal carcinoma in situ DCISS or invasive breast cancer are randomly assigned to take 100 mg soy isoflavone NovasoyTM, Archer Daniels Midland Company, Decatur, Illinois or placebo daily for three weeks prior to surgery. Plasma isoflavone levels are measured at baseline and after three weeks in both groups. Tissue isoflavone levels are measured on samples from benign breast tissues in both groups. Biomarker studies are performed on surgical specimens by immunohistochemistry and Western blot. These studies will enable us to determine if a short duration of exposure to increased tissue levels of isoflavones will modulate biomarkers of cell differentiation Cx43, adhesion E-cadherin, proliferation MIB-1, and cell growth and apoptosis bcl-2, bax, p53, p21, Rb, EGF-R, cyclin Dl, CDK5, CDK6 in benign, pre-malignant and malignant areas of breast epithelial tissues. Biomarker studies on the patients randomized on this study will be completed in early 2003.