Green Tea and Reduction of Breast Cancer Risk
RATIONALE: Green tea extract contains ingredients (catechins) that may lower the risk of breast cancer.
PURPOSE: This phase II trial is studying how well green tea extract works in preventing breast cancer compared to a placebo in postmenopausal women with high breast density.
The investigators have hypothesized that green tea consumption reduces breast cancer risk, and this effect is seen primarily in women who have the low-activity COMT genotype. The investigators will test this by evaluating the effects of green tea extract on breast cancer biomarkers including mammographic density, plasma insulin-like growth factor 1 (IGF-1), IGF binding protein 3 (IGFBP-3), estrone, estradiol, androstenedione, sex hormone binding globulin (SHBG), urinary estrogen metabolites and plasma F2-isoprostanes.
|Breast Cancer||Drug: Green tea extract supplement Other: Placebo||Phase 2|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
|Official Title:||Phase II, Randomized,Double-blind, Placebo-controlled, Study of the Efficacy of Green Tea Extract on Biomarkers of Breast Cancer Risk in High Risk Women With Differing Catechol-O-methyl Transferase (COMT) Genotypes|
- Mammographic Density [ Time Frame: Baseline and month 12 ]Percent mammographic density was measured on digital images using a computer-assisted and quantitative method.
- Circulating Concentrations of Reproductive Hormones Including Estrone, Estradiol, Androstenedione, Testosterone, and Sex Hormone Binding Globulin (SHBG) [ Time Frame: Baseline and month 12 ]Circulating levels of reproductive hormones including estrone, estradiol, androstenedione, testosterone and SHBG were measured in fasting blood samples by liquid chromatography/tandem mass spectrometry method.
- Circulating Concentrations of IGF Axis Proteins Including IGF-1 and IGFBP-3 [ Time Frame: Baseline and month 12 ]Circulating levels of IGF-1 and IGFBP-3 were measured in fasting blood samples by ELISA method.
|Study Start Date:||July 2009|
|Study Completion Date:||June 2014|
|Primary Completion Date:||June 2014 (Final data collection date for primary outcome measure)|
Experimental: Green tea extract
Green tea extract capsules containing 80.7 % total catechins (51.7 % EGCG)
Drug: Green tea extract supplement
Two green tea extract capsules twice daily after breakfast and dinner for one year
Other Name: Green tea extract: Corban green tea blend (GTB-3D)
Placebo Comparator: Sugar pill
Placebo capsules containing 50% maltodextrin, 49.5 % cellulose, and 0.5 % magnesium stearate
Two placebo capsules twice daily after breakfast and dinner for one year
Other Name: Sugar Pill
1.1 To determine the effects of green tea extract consumption (containing 800 mg EGCG per day) for 12 months on the following recognized biomarkers of breast cancer risk:
- Mammographic density
- Circulating concentrations of insulin-like growth factor 1 (IGF-1) and IGF binding protein 3 (IGFBP-3)
- Circulating concentrations of reproductive hormones (estrone, estradiol, androstenedione) and sex hormone binding globulin (SHBG)
1.2 To determine the effects of COMT genotype on the green tea extract effects described above.
2.1 To determine the effects of green tea extract consumption (containing 800 mg EGCG per day) for 12 months on the following hypothesized biomarkers of breast cancer risk:
- Urinary estrogen metabolites (estrone, estradiol, and their 2-hydroxy, 4-hydroxy, 2-methoxy, and 4-methoxy metabolites, estriol, and 16- hydroxyestrone)
- Circulating concentrations of F-2 isoprostanes, a recognized biomarker of systemic oxidative stress
2.2 To determine the effects of COMT genotype on the green tea extract effects described above.
2.3 To determine the effects of COMT genotype on catechin metabolism and excretion, as measured by circulating and urinary concentrations.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00917735
|United States, Minnesota|
|Fairview Southdale Breast Center|
|Edina, Minnesota, United States, 55435|
|Fairview Maple Grove Breast Center|
|Maple Grove, Minnesota, United States, 55369|
|University of Minnesota Medical Center (UMMC) Breast Clinic|
|Minneapolis, Minnesota, United States, 55455|
|Park Nicollet Institute|
|St. Louis Park, Minnesota, United States, 55426|
|Food Science and Nutrition, University of Minnesota|
|St. Paul, Minnesota, United States, 55108|
|Principal Investigator:||Mindy S Kurzer, Ph.D||University of Minnesota - Clinical and Translational Science Institute|