Green Tea and Reduction of Breast Cancer Risk

• ClinicalTrials.gov Identifier: NCT00917735
• Recruitment Status: Completed
• First Posted: June 10, 2009
• Results First Posted: February 22, 2016
• Last Update Posted: February 22, 2016
• Sponsor: University of Minnesota
• Collaborator: National Cancer Institute (NCI)
• Information provided by (Responsible Party): University of Minnesota

Study Description

Brief 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.

Condition or disease	Intervention/treatment	Phase
Breast Cancer	Drug: Green tea extract supplement; Other: Placebo	Phase 2

Detailed Description:

OBJECTIVES:

1. Primary:

   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:

   1. Mammographic density
   2. Circulating concentrations of insulin-like growth factor 1 (IGF-1) and IGF binding protein 3 (IGFBP-3)
   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. Secondary:

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:

1. Urinary estrogen metabolites (estrone, estradiol, and their 2-hydroxy, 4-hydroxy, 2-methoxy, and 4-methoxy metabolites, estriol, and 16- hydroxyestrone)
2. 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.

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 1075 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Quadruple (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
• Study Start Date: July 2009
• Actual Primary Completion Date: June 2014
• Actual Study Completion Date: June 2014

Arms and Interventions

Arm	Intervention/treatment
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	Other: Placebo; Two placebo capsules twice daily after breakfast and dinner for one year; Other Name: Sugar Pill

Outcome Measures

Primary Outcome Measures :

1. Mammographic Density [ Time Frame: Baseline and month 12 ]
   Percent mammographic density was measured on digital images using a computer-assisted and quantitative method.
2. 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.
3. 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.

Eligibility Criteria

• Ages Eligible for Study: 50 Years to 70 Years (Adult, Older Adult)
• Sexes Eligible for Study: Female
• Accepts Healthy Volunteers: Yes

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 <19 or >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

Contacts and Locations

Locations

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

Sponsors and Collaborators

University of Minnesota

National Cancer Institute (NCI)

Investigators

• Principal Investigator: Mindy S Kurzer, Ph.D; University of Minnesota

More Information

Additional Information:

The Minnesota Green Tea Trial (MGTT), a randomized controlled trial of the efficacy of green tea extract on biomarkers of breast cancer risk: study rationale, design, methods, and participant characteristics 

The safety of green tea extract supplementation in postmenopausal women at risk for breast cancer: results of the Minnesota Green Tea Trial 

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Samavat H, Wu AH, Ursin G, Torkelson CJ, Wang R, Yu MC, Yee D, Kurzer MS, Yuan JM. Green Tea Catechin Extract Supplementation Does Not Influence Circulating Sex Hormones and Insulin-Like Growth Factor Axis Proteins in a Randomized Controlled Trial of Postmenopausal Women at High Risk of Breast Cancer. J Nutr. 2019 Apr 1;149(4):619-627. doi: 10.1093/jn/nxy316.

Arikawa AY, Samavat H, Gross M, Kurzer MS. Plasma F(2)-isoprostanes Are Positively Associated with Glycemic Load, but Inversely Associated with Dietary Polyunsaturated Fatty Acids and Insoluble Fiber in Postmenopausal Women. J Nutr. 2017 Sep;147(9):1693-1699. doi: 10.3945/jn.117.254631. Epub 2017 Jul 26.

Samavat H, Newman AR, Wang R, Yuan JM, Wu AH, Kurzer MS. Effects of green tea catechin extract on serum lipids in postmenopausal women: a randomized, placebo-controlled clinical trial. Am J Clin Nutr. 2016 Dec;104(6):1671-1682. Epub 2016 Nov 2.

Dostal AM, Arikawa A, Espejo L, Kurzer MS. Long-Term Supplementation of Green Tea Extract Does Not Modify Adiposity or Bone Mineral Density in a Randomized Trial of Overweight and Obese Postmenopausal Women. J Nutr. 2016 Feb;146(2):256-64. doi: 10.3945/jn.115.219238. Epub 2015 Dec 23.

Dostal AM, Samavat H, Espejo L, Arikawa AY, Stendell-Hollis NR, Kurzer MS. Green Tea Extract and Catechol-O-Methyltransferase Genotype Modify Fasting Serum Insulin and Plasma Adiponectin Concentrations in a Randomized Controlled Trial of Overweight and Obese Postmenopausal Women. J Nutr. 2016 Jan;146(1):38-45. doi: 10.3945/jn.115.222414. Epub 2015 Nov 18.

• Responsible Party: University of Minnesota
• ClinicalTrials.gov Identifier: NCT00917735
• Other Study ID Numbers: 0806M36121; R01CA127236 ( U.S. NIH Grant/Contract )
• First Posted: June 10, 2009
• Results First Posted: February 22, 2016
• Last Update Posted: February 22, 2016
• Last Verified: January 2016

Keywords provided by University of Minnesota:

Green tea; Breast cancer; Prevention; COMT genotype; EGCG (Epigallocatechin gallate); Mammographic density; Reproductive hormones; IGF axis proteins; Oxidative stress

Additional relevant MeSH terms:

Breast Neoplasms; Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases