Working...
ClinicalTrials.gov
ClinicalTrials.gov Menu

Green Tea and Reduction of Breast Cancer Risk

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
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:
Collaborator:
National Cancer Institute (NCI)
Information provided by (Responsible Party):
University of Minnesota - Clinical and Translational Science Institute

Study Type Interventional
Study Design Allocation: Randomized;   Intervention Model: Parallel Assignment;   Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor);   Primary Purpose: Prevention
Condition Breast Cancer
Interventions Drug: Green tea extract supplement
Other: Placebo
Enrollment 1075
Recruitment Details August 2009 through April 2013
Pre-assignment Details Prior to randomization, participants went through a screening clinic visit in which anthropometric characteristics and blood pressure were measured. In addition, blood was drawn to assess catechol-O-methyltransferase (COMT) genotype, hepatic function, and serological markers of hepatitis B and C virus.
Arm/Group Title Green Tea Extract Sugar Pill
Hide Arm/Group Description Green tea extract (GTE) supplement: Two green tea extract capsules twice daily after breakfast and dinner for one year. GTE was a decaffeinated green tea extract, and each capsule contained a total of 328.8 ± 28.9 mg catechins including 210.7 ± 11.0 mg of epigallocatechin gallate (EGCG). Placebo: Two placebo capsules twice daily after breakfast and dinner for one year. Placebo capsules contained maltodextrin, cellulose, and magnesium stearate.
Period Title: Overall Study
Started 538 537
Completed 463 474
Not Completed 75 63
Arm/Group Title Green Tea Extract Sugar Pill Total
Hide Arm/Group Description Green tea extract supplement: Two green tea extract capsules twice daily after breakfast and dinner for one year Placebo: Two placebo capsules twice daily after breakfast and dinner for one year Total of all reporting groups
Overall Number of Baseline Participants 538 537 1075
Hide Baseline Analysis Population Description
[Not Specified]
Age, Continuous  
Mean (Standard Deviation)
Unit of measure:  Years
Number Analyzed 538 participants 537 participants 1075 participants
59.9  (5.0) 59.6  (5.1) 59.8  (5.02)
Sex: Female, Male  
Measure Type: Count of Participants
Unit of measure:  Participants
Number Analyzed 538 participants 537 participants 1075 participants
Female
538
 100.0%
537
 100.0%
1075
 100.0%
Male
0
   0.0%
0
   0.0%
0
   0.0%
Ethnicity (NIH/OMB)  
Measure Type: Count of Participants
Unit of measure:  Participants
Number Analyzed 538 participants 537 participants 1075 participants
Hispanic or Latino
5
   0.9%
6
   1.1%
11
   1.0%
Not Hispanic or Latino
516
  95.9%
510
  95.0%
1026
  95.4%
Unknown or Not Reported
17
   3.2%
21
   3.9%
38
   3.5%
Race (NIH/OMB)  
Measure Type: Count of Participants
Unit of measure:  Participants
Number Analyzed 538 participants 537 participants 1075 participants
American Indian or Alaska Native
0
   0.0%
0
   0.0%
0
   0.0%
Asian
3
   0.6%
7
   1.3%
10
   0.9%
Native Hawaiian or Other Pacific Islander
0
   0.0%
0
   0.0%
0
   0.0%
Black or African American
4
   0.7%
7
   1.3%
11
   1.0%
White
515
  95.7%
505
  94.0%
1020
  94.9%
More than one race
4
   0.7%
2
   0.4%
6
   0.6%
Unknown or Not Reported
12
   2.2%
16
   3.0%
28
   2.6%
Region of Enrollment  
Measure Type: Number
Unit of measure:  Participants
United States Number Analyzed 538 participants 537 participants 1075 participants
538 537 1075
Height  
Mean (Standard Deviation)
Unit of measure:  Cm
Number Analyzed 538 participants 537 participants 1075 participants
163.5  (6.3) 164.3  (6.2) 163.9  (6.2)
Weight  
Mean (Standard Deviation)
Unit of measure:  Kg
Number Analyzed 538 participants 537 participants 1075 participants
67.4  (10.6) 67.9  (10.5) 67.4  (10.5)
Waist-to-hip ratio  
Mean (Standard Deviation)
Unit of measure:  Ratio
Number Analyzed 538 participants 537 participants 1075 participants
0.84  (0.1) 0.83  (0.1) 0.83  (0.07)
1.Primary Outcome
Title Mammographic Density
Hide Description Percent mammographic density was measured on digital images using a computer-assisted and quantitative method.
Time Frame Baseline and month 12
Hide Outcome Measure Data
Hide Analysis Population Description
Mammographic density at baseline and month 12
Arm/Group Title Green Tea Extract Sugar Pill
Hide Arm/Group Description:
Green tea extract (GTE) supplement: Two green tea extract capsules twice daily after breakfast and dinner for one year. GTE was a decaffeinated green tea extract, and each capsule contained a total of 328.8 ± 28.9 mg catechins including 210.7 ± 11.0 mg of EGCG.
Placebo: Two placebo capsules twice daily after breakfast and dinner for one year. Placebo capsules contained maltodextrin, cellulose, and magnesium stearate.
Overall Number of Participants Analyzed 462 470
Geometric Mean (95% Confidence Interval)
Unit of Measure: Percent
Percent mammographic density at baseline
22.71
(21.39 to 24.10)
21.84
(20.59 to 23.17)
Percent mammographic density at month 12
22.09
(20.77 to 23.50)
21.13
(19.88 to 22.47)
2.Primary Outcome
Title Circulating Concentrations of Reproductive Hormones Including Estrone, Estradiol, Androstenedione, Testosterone, and Sex Hormone Binding Globulin (SHBG)
Hide Description 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.
Time Frame Baseline and month 12
Hide Outcome Measure Data
Hide Analysis Population Description
Circulating concentrations of reproductive hormones including estrone, estradiol, androstenedione, testosterone, sex hormone binding globulin (SHBG) at baseline and month 12
Arm/Group Title Green Tea Extract Sugar Pill
Hide Arm/Group Description:
Green tea extract (GTE) supplement: Two green tea extract capsules twice daily after breakfast and dinner for one year. GTE was a decaffeinated green tea extract, and each capsule contained a total of 328.8 ± 28.9 mg catechins including 210.7 ± 11.0 mg of EGCG.
Placebo: Two placebo capsules twice daily after breakfast and dinner for one year. Placebo capsules contained maltodextrin, cellulose, and magnesium stearate.
Overall Number of Participants Analyzed 463 474
Geometric Mean (95% Confidence Interval)
Unit of Measure: pg/ml
Circulating estrone at baseline
22.8
(21.6 to 24.0)
23.6
(22.4 to 24.9)
Circulating estrone at month 12
22.5
(21.3 to 23.7)
22.4
(21.3 to 23.6)
Circulating estradiol at baseline
3.4
(3.1 to 3.8)
3.7
(3.3 to 4.1)
Circulating estradiol at month 12
3.7
(3.4 to 4.1)
3.1
(2.8 to 3.5)
Circulating androstenedione at baseline
479.8
(459.4 to 501.2)
507.2
(485.9 to 529.5)
Circulating androstenedione at month 12
468.8
(450.2 to 488.3)
479.5
(460.6 to 499.1)
Circulating testosterone at baseline
151.0
(142.7 to 159.7)
161.6
(152.8 to 170.8)
Circulating testosterone at month 12
158.1
(149.9 to 166.9)
155.1
(147.1 to 163.6)
Circulating SHBG at baseline
68.1
(65.0 to 71.3)
69.1
(66.0 to 72.3)
Circulating SHBG at month 12
68.7
(65.5 to 72.0)
68.7
(65.5 to 72.0)
3.Primary Outcome
Title Circulating Concentrations of IGF Axis Proteins Including IGF-1 and IGFBP-3
Hide Description Circulating levels of IGF-1 and IGFBP-3 were measured in fasting blood samples by ELISA method.
Time Frame Baseline and month 12
Hide Outcome Measure Data
Hide Analysis Population Description
Circulating concentrations of IGF axis proteins including insulin-like growth factor (IGF-1) and IGF binding protein 3 (IGFBP-3) at baseline and month 12
Arm/Group Title Green Tea Extract Sugar Pill
Hide Arm/Group Description:
Green tea extract (GTE) supplement: Two green tea extract capsules twice daily after breakfast and dinner for one year. GTE was a decaffeinated green tea extract, and each capsule contained a total of 328.8 ± 28.9 mg catechins including 210.7 ± 11.0 mg of EGCG.
Placebo: Two placebo capsules twice daily after breakfast and dinner for one year. Placebo capsules contained maltodextrin, cellulose, and magnesium stearate.
Overall Number of Participants Analyzed 462 473
Geometric Mean (95% Confidence Interval)
Unit of Measure: ng/ml
Circulating IGF-1 at baseline
87.5
(85.3 to 89.8)
88.3
(86.1 to 90.5)
Circulating IGF-1 at month 12
83.7
(81.6 to 85.8)
83.1
(81.0 to 85.2)
Circulating IGFBP-3 at baseline
2048.0
(2008.9 to 2088.0)
2047.6
(2008.9 to 2087.1)
Circulating IGFBP-3 at month 12
2048.1
(2008.0 to 2089.1)
2040.7
(2001.0 to 2081.0)
Time Frame 5 years
Adverse Event Reporting Description Adverse event information was coded and graded using the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE), version 4.03.
 
Arm/Group Title Green Tea Extract Sugar Pill
Hide Arm/Group Description Green tea extract (GTE) supplement: Two green tea extract capsules twice daily after breakfast and dinner for one year. GTE was a decaffeinated green tea extract, and each capsule contained a total of 328.8 ± 28.9 mg catechins including 210.7 ± 11.0 mg of EGCG. Placebo: Two placebo capsules twice daily after breakfast and dinner for one year. Placebo capsules contained maltodextrin, cellulose, and magnesium stearate.
All-Cause Mortality
Green Tea Extract Sugar Pill
Affected / at Risk (%) Affected / at Risk (%)
Total   --/--      --/--    
Show Serious Adverse Events Hide Serious Adverse Events
Green Tea Extract Sugar Pill
Affected / at Risk (%) # Events Affected / at Risk (%) # Events
Total   12/538 (2.23%)      8/537 (1.49%)    
Blood and lymphatic system disorders     
Hypertension  1  0/538 (0.00%)  0 1/537 (0.19%)  1
Ear and labyrinth disorders     
Acoustic Neuroma  1  1/538 (0.19%)  1 0/537 (0.00%)  0
Gastrointestinal disorders     
Diarrhea  1  0/538 (0.00%)  0 1/537 (0.19%)  1
Colitis  1  1/538 (0.19%)  1 0/537 (0.00%)  0
Hepatobiliary disorders     
Elevated ALT or AST enzyme  1  7/538 (1.30%)  9 0/537 (0.00%)  0
Neoplasms benign, malignant and unspecified (incl cysts and polyps)     
Diagnosis of Uterine Cancer  1  0/538 (0.00%)  0 2/537 (0.37%)  2
Social circumstances     
Motorcycle accident  1  0/538 (0.00%)  0 1/537 (0.19%)  1
Fall  1  0/538 (0.00%)  0 1/537 (0.19%)  1
Surgical and medical procedures     
Surgery  1  3/538 (0.56%)  3 2/537 (0.37%)  2
Indicates events were collected by systematic assessment
1
Term from vocabulary, CTCAE (4.0)
Show Other (Not Including Serious) Adverse Events Hide Other (Not Including Serious) Adverse Events
Frequency Threshold for Reporting Other Adverse Events 0%
Green Tea Extract Sugar Pill
Affected / at Risk (%) # Events Affected / at Risk (%) # Events
Total   407/538 (75.65%)      391/537 (72.81%)    
Gastrointestinal disorders     
Nausea  1  235/538 (43.68%)  235 184/537 (34.26%)  184
General disorders     
General  1  69/538 (12.83%)  69 77/537 (14.34%)  77
Other  1  280/538 (52.04%)  280 218/537 (40.60%)  218
Infections and infestations     
Infections  1  216/538 (40.15%)  216 217/537 (40.41%)  217
Musculoskeletal and connective tissue disorders     
Musuclar  1  65/538 (12.08%)  65 69/537 (12.85%)  69
Respiratory, thoracic and mediastinal disorders     
Respitory  1  122/538 (22.68%)  122 122/537 (22.72%)  122
Vascular disorders     
Vascular  1  154/538 (28.62%)  154 144/537 (26.82%)  144
Indicates events were collected by systematic assessment
1
Term from vocabulary, CTCAE (4.0)
We had limited success in recruiting minority populations.
Certain Agreements
Principal Investigators are NOT employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.
Results Point of Contact
Name/Title: Dr. Mindy Kurzer
Organization: University of Minnesota
Phone: 612-624-9789
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: University of Minnesota - Clinical and Translational Science Institute
ClinicalTrials.gov Identifier: NCT00917735     History of Changes
Other Study ID Numbers: 0806M36121
R01CA127236 ( U.S. NIH Grant/Contract )
First Submitted: June 8, 2009
First Posted: June 10, 2009
Results First Submitted: July 29, 2015
Results First Posted: February 22, 2016
Last Update Posted: February 22, 2016