Effect of Dietary Soy on Estrogens in Breast Fluid, Blood, and Urine Samples From Healthy Women

Phase 3

Completed

• Conditions: Breast Cancer; Healthy, no Evidence of Disease
• Interventions: Dietary Supplement: soy isoflavones

• Registration Number: NCT00513916
• Lead Sponsor: University of Hawaii Cancer Research Center

Brief Summary

RATIONALE: Chemoprevention is the use of certain drugs to keep cancer from forming. Eating a diet high in isoflavones, compounds found in soy foods, may keep cancer from forming.

PURPOSE: This randomized phase III trial is studying the effects of dietary soy on estrogens in breast fluid, blood, and urine samples from healthy women.

Detailed Description

OBJECTIVES:

* Examine the effects of two daily servings of soy on estrogen levels in nipple aspirate fluid (NAF) and serum.

* Investigate cytologic patterns of epithelial breast cells obtained from NAF as a measure of proliferation in relation to soy intake.

* Explore the effect of two daily servings of soy on cytochrome alterations of estrogen metabolism as expressed in the formation of urinary 2-, 16α-, and 4-hydroxy estrogen metabolites.

* Compare estrogen levels in NAF and serum measured at the same time during the luteal phase.

OUTLINE: This is a multicenter study. Participants are randomized to 1 of 2 intervention arms.

* Arm I: Participants partake in a high soy diet consisting of 2 daily soy servings (approximately 50mg isoflavones). The choice of soy foods will include ½ cup of tofu, ¾ cup of soy milk, or ¼ cup of soy nuts. Replacement of currently consumed foods with soy foods will be encouraged.

* Arm II: Participants will be asked to keep their soy intake below 3 servings per week. The participants will also receive general nutrition counseling.

In both arms, intervention continues for 6 months. After 6 months, participants undergo a 1-month washout period and then cross-over to the other intervention arm.

Nipple aspirate fluid, urine, and blood samples are collected periodically to measure laboratory endpoints.

Study Timeline

• Study Start: 2006-07
• Study First Submitted: 2007-08-08
• Study First Submitted QC: 2007-08-08
• Study First Posted: 2007-08-09
• Status Verified: 2009-04
• Primary Completion: 2011-02
• Study Completion: 2012-02
• Last Update Submitted: 2013-12-18
• Last Update Posted: 2013-12-19

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 100

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Arm I	soy isoflavones	Participants partake in a high soy diet consisting of 2 daily soy servings (approximately 50mg isoflavones). The choice of soy foods will include ½ cup of tofu, ¾ cup of soy milk, or ¼ cup of soy nuts. Replacement of currently consumed foods with soy foods will be encouraged.
Arm II	soy isoflavones	Participants will be asked to keep their soy intake below 3 servings per week. The participants will also receive general nutrition counseling.

Primary Outcome Measures

Name	Time	Method
Effect of two daily servings of soy on estrogen levels in nipple aspirate fluid (NAF) and serum
Cytologic patterns of epithelial breast cells obtained from NAF
Effect of two daily servings of soy on cytochrome alterations of estrogen metabolism as expressed in the formation of urinary 2-, 16α-, and 4-hydroxy estrogen metabolites
Comparison of estrogen levels in NAF and serum measured at the same time during luteal phase

Trial Locations

Locations (1)

Cancer Research Center of Hawaii; 🇺🇸 Honolulu, Hawaii, United States