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Genistein in Preventing Breast or Endometrial Cancer in Healthy Postmenopausal Women

This study has been completed.
National Cancer Institute (NCI)
Information provided by (Responsible Party):
UNC Lineberger Comprehensive Cancer Center Identifier:
First received: December 8, 2004
Last updated: May 17, 2013
Last verified: May 2013

RATIONALE: Chemoprevention therapy is the use of certain drugs to try to prevent the development or recurrence of cancer. The use of genistein may be effective in preventing breast or endometrial cancer.

PURPOSE: This randomized phase I trial is studying the effectiveness of genistein in preventing breast or endometrial cancer in healthy postmenopausal women.

Condition Intervention Phase
Breast Cancer
Endometrial Cancer
Dietary Supplement: Genistein
Dietary Supplement: Placebo
Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Phase I Multiple Dose Clinical Study of Soy Isoflavones in Healthy, Post-Menopausal Women

Resource links provided by NLM:

Further study details as provided by UNC Lineberger Comprehensive Cancer Center:

Primary Outcome Measures:
  • Efficacy of genistein on DNA and apoptosis [ Time Frame: 112 days ]
    Compare the effects of genistein vs placebo on DNA damage and apoptosis by conducting COMET, TUNEL, Caspase-3, and AP site assays in healthy postmenopausal women.

Enrollment: 30
Study Start Date: March 2004
Study Completion Date: July 2006
Primary Completion Date: July 2005 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Arm I
Dietary Supplement: Genistein
oral Genistein twice daily on days 1-84
Other Name: PTI G-2535
Placebo Comparator: Arm II
Dietary Supplement: Placebo
oral Placebo twice daily on days 1-84

Detailed Description:


  • Compare the effects of genistein vs placebo on DNA damage and apoptosis by conducting COMET, TUNEL, Caspase-3, and AP site assays in healthy postmenopausal women.
  • Compare the effects of these drugs on gene expression in an estrogen-sensitive tissue by oligoarray profiling in these participants.
  • Determine the effect of genistein on estrogenic effects by self-reported side effects, measurement of sex hormone-binding globulin, follicle-stimulating hormone, luteinizing hormone, and estrogen levels, and expression of known estrogen-sensitive genes in these participants.

OUTLINE: This is a randomized, double-blind, placebo-controlled study. Participants are stratified according to their study ID numbers. Participants are randomized to 1 of 2 treatment arms.

  • Arm I: Participants receive oral genistein twice daily on days 1-84.
  • Arm II: Participants receive oral placebo twice daily on days 1-84. In both arms, treatment continues in the absence of dysplasia, malignancy, unacceptable toxicity, or gross noncompliance.

Participants are followed at days 7, 14, 28, 56, and 84 during study treatment and at day 28 after completion of study treatment.

PROJECTED ACCRUAL: A total of 30 participants (20 for arm I and 10 for arm II) will be accrued for this study.


Ages Eligible for Study:   45 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes


  • Healthy participants

    • Papanicolaou test (pap smear) normal within the past 13 months
    • Mammogram normal within the past 13 months
  • No history of breast cancer
  • Not at high-risk (5-year risk < 1.9%) for breast cancer according to NCI's Breast Cancer Risk Assessment Tool
  • Hormone receptor status:

    • Not specified



  • 45 to 70


  • Female

Menopausal status

  • Postmenopausal

    • Last spontaneous menstrual bleeding > 12 months ago

Performance status

  • ECOG 0-2

Life expectancy

  • Not specified


  • WBC ≥ 3,500/mm^3
  • Platelet count ≥ 100,000/mm^3


  • Bilirubin ≤ 2.0 mg/dL
  • ALT and AST < 2 times normal
  • No significant abnormality of the liver by physical exam


  • Creatinine < 2.0 mg/dL


  • No significant cardiac disease
  • No New York Heart Association class III or IV heart disease
  • No significant abnormality of the heart by physical exam


  • No significant abnormality of the lung by physical exam


  • Body mass index < 35
  • Follicle-stimulating hormone > 27 mIU/mL
  • Thyroid or endocrine function test normal
  • Alcohol intake ≤ 2 drinks/day or ≤14 drinks/week
  • Not pregnant
  • No intermediate equol values (≥10 ug/L to ≤ 20 ug/L) on soy challenge
  • No history of seizures
  • No significant abnormality of the spleen or other abdominal organs by physical exam
  • No neurologic abnormality by physical exam
  • No significant metabolic abnormality on the biochemical screen
  • No history of substance abuse or addiction
  • No tobacco use
  • No diets containing > 20 mg of genistein/day or > 40 mg isoflavone/day
  • No known intolerance to soy
  • No other serious medical illness
  • No active malignancy or malignancy initially diagnosed within the past 2 years except curatively treated nonmelanoma skin cancer


Biologic therapy

  • Not specified


  • More than 2 years since prior chemotherapy
  • No concurrent chemotherapy

Endocrine therapy

  • More than 3 months since prior hormonal or estrogen therapy
  • More than 3 months since prior tamoxifen or other selective estrogen-receptor modulators
  • More than 1 month since prior supplements containing phytoestrogens or that have estrogenic side effects (soy isoflavones or PC-SPECS)
  • No concurrent thyroid medication

    • Other concurrent endocrine medication allowed provided medication was initiated ≥ 3 months before study entry AND participant has been on a stable regimen for the past 3 months


  • Not specified


  • No prior hysterectomy or oophorectomy


  • More than 3 months since prior antibiotics
  Contacts and Locations
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Please refer to this study by its identifier: NCT00099008

United States, North Carolina
Lineberger Comprehensive Cancer Center at University of North Carolina - Chapel Hill
Chapel Hill, North Carolina, United States, 27599-7295
Sponsors and Collaborators
UNC Lineberger Comprehensive Cancer Center
National Cancer Institute (NCI)
Principal Investigator: Steven H. Zeisel, MD, PhD UNC Lineberger Comprehensive Cancer Center
  More Information

Responsible Party: UNC Lineberger Comprehensive Cancer Center Identifier: NCT00099008     History of Changes
Other Study ID Numbers: UNC-GCRC-2107
CDR0000393450 ( Other Identifier: PDQ number )
Study First Received: December 8, 2004
Last Updated: May 17, 2013

Keywords provided by UNC Lineberger Comprehensive Cancer Center:
breast cancer
endometrial cancer

Additional relevant MeSH terms:
Endometrial Neoplasms
Uterine Neoplasms
Genital Neoplasms, Female
Urogenital Neoplasms
Neoplasms by Site
Uterine Diseases
Genital Diseases, Female
Anticarcinogenic Agents
Protective Agents
Physiological Effects of Drugs
Antineoplastic Agents
Protein Kinase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Estrogens, Non-Steroidal
Hormones, Hormone Substitutes, and Hormone Antagonists processed this record on May 25, 2017