Soy Isoflavones and Breast Cancer Risk Reduction

Study Overview
=================
Brief Summary
-----------------
Soy consumption has been associated with reduced risk for developing breast cancer. Soy contains isoflavones which are weak estrogens. The roles of soy isoflavones in reducing breast cancer risk are currently unclear. Breast density has been considered as a breast cancer risk marker. We hypothesize that because isoflavones have estrogen-like activities, breast density and possibly bone density will be lower in women on soy-isoflavones.

Detailed Description
-----------------
This is a randomized, double-blind study, with two arms and 100 women in each arm. Premenopausal women will be recruited and randomly allocated to take one of the two different dietary supplements in pills daily for 2 years. The two supplements are soy isoflavones (treatment) and placebo (carbohydrates). Both treatment and placebo pills will contain multi-vitamins and minerals. Multiple blood, urine, and breast fluid samples will be obtained before and during the dietary supplement periods and analyzed for biomarkers of breast cancer risk. At baseline and after the intervention period, breast density and bone density will be assessed by radiologic techniques. The efficacy of the dietary intervention will be determined by comparing mean changes of serum markers for breast cancer risk,dense breast tissue, and bone mineral density over the two year dietary intervention period in the two supplement groups with adjustment for baseline values and individual patient characteristics of interest. We predict that 2 years of soy isoflavone supplement will reduce breast density, which may be explained by individual changes in serum markers of breast cancer risk.

Official Title
-----------------
Mammographic Density and Soy Isoflavones

Conditions
-----------------
Breast Cancer

Intervention / Treatment
-----------------
* Dietary Supplement: isoflavones
* Dietary Supplement: carbohydrate


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: healthy premenopausal women 30 to 42 years old normal mammograms regular menstrual cycles Exclusion Criteria: abnormal mammograms first degree relatives with breast cancer pregnant or lactating peri- or post-menopause breast augmentation, reduction or lifting on oral contraceptive medications or exogenous hormones medically prescribed diets allergic reaction to soy products

Ages Eligible for Study
-----------------
Minimum Age: 30 Years
Maximum Age: 42 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: One group received soy isoflavones (60 mg daidzein, 60 mg gensitein and 16.6 mg glycitein, all as aglycone equivalent) Another group, carbohydrate filler
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>soy isoflavones | Dietary Supplement: isoflavones<br>* soy isoflavones: Each tablet contains 246 mg Novasoy, 676 mg calcium, 15 mg riboflavin, and other innert materials to a total weight of 1000 mg. Subject takes two isoflavone tablets plus 1 multi-vitamin per day for five days per week for upto 2 years.<br>* Other names: Isoflavone pill;|
| Placebo Comparator: 2<br>carbohydrates (maltodextrin) | Dietary Supplement: carbohydrate<br>* carbohydrate: 246 mg maltodextrin, 676 mg calcium, 15 mg riboflavin and other innert ingredients to a total weight of 1000 mg per tablet. subject takes two tablets plus one multivitamin per day for five days per week for upto 2 years.<br>* Other names: Sugar pill;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Breast density | Amount or percentage of fibroglandular breast tissue in a breast as measured by digital mammography or by magnetic resonance imaging | one or two years after dietary supplements | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| bone density | Bone mineral density of whole body, hip and spine as measured by dual x-ray absorptiometry | one or two years after dietary supplement | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
soy, isoflavones, phytoestrogens, prevention, mammographic density, bone density