Soy Protein and Breast Cancer Risk Reduction

Study Overview
=================
Brief Summary
-----------------
Soy consumption has been associated with reduced risk for developing breast cancer. Ovarian hormones and breast density are considered breast cancer risk markers. We propose to test the hypothesis that consumption of soy protein reduces ovarian steroid hormones and results in a corresponding reduction in breast density comparing to casein protein.

Detailed Description
-----------------
The aims will be tested by conducting 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 two different dietary supplements daily for 2 years. The two test diets soy protein drink and caseinate protein drink. Multiple blood, urine, and breast fluid samples will be obtained before and during the dietary intervention period and analyzed for ovarian hormones. At baseline and after the intervention period, breast density, and bone density will be assessed by radiological techniques at baseline and 1 yr and 2 yr after protein drink supplementation. The efficacy of the dietary intervention will be determined by comparing mean changes of ovarian steroids, and density of the breast and bone tissues over the 2 year dietary intervention period in the two diet groups with adjustment for baseline values and individual patient characteristics of interest. We predict that 2 years of soya dietary supplements will reduce breast density, which will be explained by individual hormonal changes.

Official Title
-----------------
Soybean Diet and Breast Density

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

Intervention / Treatment
-----------------
* Dietary Supplement: soy milk
* Dietary Supplement: cow's milk


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: healthy premenopausal women 30 to 40 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, and lifting on oral contraceptive medications or exogenous hormones medically prescribed diets allergic reaction to soy or cow's milk

Ages Eligible for Study
-----------------
Minimum Age: 30 Years
Maximum Age: 40 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: Randomized, double-blind, placebo controlled, 2 parallel groups
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Soy milk<br>Subjects will consume two soy milk drinks from the content of 2 sachets (40 g isoflavone-free soy protein and 600 mg calcium) in place of a small meal, five days per week. Each sachet will contain 20 g soy protein and 300 mg calcium. Content of sachets will be mixed with  1.6 liter of water for ingestion. | Dietary Supplement: soy milk<br>* Each drink contained soy protein, fat, and carbohydrates calcium and phosphorous to give a total energy of 177.8 kcal. Subjects took two drinks per day.<br>* Other names: Not applicable, research product;|
| Placebo Comparator: Cow's milk<br>Subjects will consume two cow's milk drinks from the content of 2 sachets (40 g cow's milk protein, casein, and 600 mg calcium) in place of a small meal, five days per week. Each sachet will contain 20 g cow's milk protein and 300 mg calcium. Content of sachets will be mixed with  1.6 liter of water for ingestion. Casein is free of ovarian hormones. | Dietary Supplement: cow's milk<br>* Each drink contained casein, fat, carbohydrates, calcium and phosphorous to give a total energy of 178.6 kcal. Subjects took two drinks per day.<br>* Other names: Not applicable, research product;|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| mammographic density | breast images to be measured by digital mammography and breast magnetic resonance imaging protocol, breast density is percent of fibroglandular tissue (radiologically dense) in whole breast tissue | once per year for two years | 
| bone density | Bone mineral content (gm) or bone mineral density (gm/cm2) to be measured by dual energy x-ray absorptiometry (DEXA) once at baseline, and then yearly after supplementation for up to 2 years. | once per year for two years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Estradiol (pg/ml) | Serum will be measured for estrogen (pg/ml), 4 times at baseline, and thereafter at 3-monthly interval for up to 2 years of protein drink supplementation | 4 measurements at baseline and once every three months after protein drink supplements for up to 2 years. | 
| Progesterone (ng/ml) | Serum will be measured for progesterone (ng/ml), 4 times at baseline, and thereafter at 3-monthly interval for up to 2 years of protein drink supplementation | 4 measurements at baseline and once every three months after protein drink supplements for up to 2 years. | 
| Blood will be measured for standard clinical chemistries | Serum will be measured for for blood chemistries , 4 times at baseline, and thereafter at 3-monthly interval for up to 2 years of protein drink supplementation | 4 measurements at baseline and once every three months after protein drink supplements for up to 2 years. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
soy diet, breast cancer, ovarian hormones, breast density, prevention