Randomized Controlled Study of Soy on Breast Tissues
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: There is accumulating evidence from observational epidemiologic studies that soy intake may be an attractive chemoprevention strategy for women with ductal carcinoma in situ (DCIS) or are at ‘high-risk’ for other reasons, including known BRCA1/BRCA2 mutations or a high (1.7 or greater) five-year Gail score. Current treatment modalities for DCIS patients are surgical resection (local excision or mastectomy), radiation therapy and tamoxifen therapy. Although a beneficial effect from tamoxifen for DCIS is well established, no more than about 25% of DCIS patients complete a 5-year course of tamoxifen, because of side effects or other reasons. While mastectomy and
 
 tamoxifen are prevention options for some high-risk women, these are not acceptable prevention strategies for the majority of women. 
 
 
 
 
 
 
 
 The overall objective of this translational project is to determine whether women with DCIS and other ‘high-risk’ women benefit from soy supplementation. We will evaluate whether there are significant beneficial changes from baseline in MRI volume, and markers of breast cell proliferation and apoptosis in the breast of ‘high-risk’ women who are randomized to soy compared to placebo for 1 year. Specifically, we will assess whether: 
 
 
 
 1) magnetic resonance imaging (MRI) volume (equivalent to 3-dimensional mammographic density) is reduced in high-risk women or those with DCIS who are supplemented daily with soy (25 g soy protein) compared to placebo (25 g milk protein) for 1 year. 
 
 
 
 2) cell proliferation and apoptosis, as measured by Ki67 and caspase 3 staining, respectively, of breast epithelial cells is altered with soy treatment. 
 
 
 
 
 
 
 
 We will offer soy/placebo agents to women who are not receiving other treatments. Women between the ages of 30 and 75, all racial/ethnic background, not regular (weekly) soy consumers or current users of exogenous hormonal therapy (e.g., OC, HT, soy estrogens) will be eligible. Mammogram, MRI, breast biopsy, blood and urine specimens, and anthropometric measures will be obtained at baseline and at the completion of 1 year of intervention. Blood/urine specimens and anthropometric breast measurements will be performed. Urinary soy isoflavone levels will be measured to assess compliance. For DCIS patients, the baseline and year 1 breast biopsies will be conducted on the unaffected breast. For high-risk women with DCIS, we will conduct the breast biopsies on the breast on the opposite side to their dominant arm. In pre-menopausal women, we will conduct the MRI, breast biopsies and collect blood/urine specimens around the mid-luteal phase of the menstrual cycle.
 
 
 
 
 
 
 
 There are currently few treatment alternatives for women with DCIS and few non-invasive prevention strategies for ‘high-risk’ women. This research is aimed at addressing an important research need using soy, a dietary agent that is safe, affordable, and has been a staple in many Asian populations for centuries. Results we obtain from this proposed study are potentially applicable to women of all racial/ethnic backgrounds.