Phase 2 N=1,075 Randomized Quadruple-blind Prevention

Green Tea and Reduction of Breast Cancer Risk

Breast Cancer

Bottom Line

View on ClinicalTrials.gov: NCT00917735 ↗

Enrolled (actual)

1,075

Serious AEs

1.9%

Results posted

Feb 2016

Primary outcome: Primary: Mammographic Density — 22.71; 21.84; 22.09; 21.13 Percent

Study Design & Population

Study type: Interventional
Phase: Phase 2
Interventions: Green tea extract supplement (Drug); Placebo (Other)
Age: Adult, Older Adult · 50+ yrs
Sex: Female
Sponsor: University of Minnesota
Primary completion: Jun 2014

Outcome Measures

Outcome	Result	p-value
PRIMARY Mammographic Density	22.71; 21.84; 22.09; 21.13	—
PRIMARY Circulating Concentrations of Reproductive Hormones Including Estrone, Estradiol, Androstenedione, Testosterone, and Sex Hormone Binding Globulin (SHBG)	22.8; 23.6; 22.5; 22.4; 3.4; 3.7	—
PRIMARY Circulating Concentrations of IGF Axis Proteins Including IGF-1 and IGFBP-3	87.5; 88.3; 83.7; 83.1; 2048.0; 2047.6	—

Summary

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.

Eligibility Criteria

Inclusion Criteria

Signed informed consent
Healthy postmenopausal women aged 50-70 years
"Heterogeneously dense" (51-75% glandular) or "extremely dense" (>75%glandular) breasts
Willing to avoid consumption of green tea for 1 year

Exclusion Criteria

Positive serological markers of hepatitis B or hepatitis C infections
Elevated levels of liver enzymes
Recent (within 6 mo) or current hormone or hormone modification therapy, including systemic hormone replacement therapy, SERMS and aromatase inhibitors
Current smoker of cigarettes or other tobacco products
BMI 40 kg/m2
Weight change > 10 lbs during the previous year
History of breast cancer or proliferative breast disease
Regular consumption of > 7 alcoholic drinks/wk
Regular consumption of green tea (>1 cup/wk)
Recent (within 6 mo) or current use of chemopreventive agents such as tamoxifen, raloxifene or aromatase inhibitors
Participation in any weight loss or weight gain studies
Currently taking Methotrexate or Enbrel
History of ovarian cancer
Any form of cancer in the last 5 years
Presence of implants

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT00917735). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.