Clinical Trial: Genistein in Preventing Breast or Endometrial Cancer in Healthy Postmenopausal Women

This study is no longer recruiting patients.

Sponsors and Collaborators: UNC Lineberger Comprehensive Cancer Center
National Cancer Institute (NCI)
Information provided by: National Cancer Institute (NCI)


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 Treatment or Intervention Phase
Breast Cancer
Endometrial Cancer
 Drug: genistein
 Procedure: biologically based therapies
 Procedure: cancer prevention intervention
 Procedure: chemoprevention of cancer
 Procedure: complementary and alternative therapy
 Procedure: dietary intervention
 Procedure: herbal medicine / botanical therapy
 Procedure: nutritional supplementation
 Procedure: phytoestrogen therapy
Phase I

MedlinePlus related topics:  Breast Cancer;   Uterine Cancer
Genetics Home Reference related topics:  breast cancer

Study Type: Interventional
Study Design: Prevention

Official Title: Phase I Randomized Chemoprevention Study of Genistein in Healthy Postmenopausal Women

Further Study Details: 


  • Compare the effects of genistein vs placebo on DNA damage and apoptosis by conducting COMET assays, TUNEL assays, Caspase-3 assays, 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 or malignancy or unacceptable toxicity.

Participants are followed at 28 days.

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


Genders Eligible for Study:  Both

Accepts Healthy Volunteers



  • 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 ≥ 1.7%) for breast cancer according to NCI's Breast Cancer Risk Assessment Tool
  • Hormone receptor status:
  • Not specified


  • Postmenopausal


  • Female

Menopausal status

  • Postmenopausal
  • Last spontaneous menstrual bleeding > 12 months ago

Performance status

  • ECOG 0-2

Life expectancy

  • At least 6 months


  • 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 > 30 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


  • 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



  • More than 3 months since prior antibiotics

Location Information

North Carolina
      Lineberger Comprehensive Cancer Center at University of North Carolina - Chapel Hill, Chapel Hill,  North Carolina,  27599-7295,  United States

Study chairs or principal investigators

Steven H. Zeisel, MD, PhD,  Principal Investigator,  UNC Lineberger Comprehensive Cancer Center   

More Information

Clinical trial summary from the National Cancer Institute's PDQ® database

Study ID Numbers:  CDR0000393450; UNC-GCRC-2107
Record last reviewed:  January 2005
Last Updated:  January 10, 2005
Record first received:  December 8, 2004 Identifier:  NCT00099008
Health Authority: United States: Federal Government processed this record on 2005-04-08

Cache Date: April 9, 2005