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Green Tea Extracts for the Prevention of Colorectal Adenomas and Colorectal Cancer

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. Identifier: NCT02321969
Recruitment Status : Completed
First Posted : December 22, 2014
Last Update Posted : October 28, 2015
Information provided by (Responsible Party):
Seoul National University Hospital

Brief Summary:
Experimental studies have shown the chemopreventive properties of green tea extract (GTE) on colorectal cancer. And colorectal adenomas are precursors to colorectal cancers. The aim of this study is to determine the preventive effect of GTE supplements on metachronous colorectal adenomas by giving GTE tablets of which are equivalent of 9 cup-of-green tea per day (0.9 g/day GTE, 0.6 g/day Epigallocatechin gallate (EGCG).

Condition or disease Intervention/treatment Phase
Neoplasms, Colorectal Dietary Supplement: GTE (green tea extract) Not Applicable

Detailed Description:
The subjects who had undergone complete removal of colorectal adenomas by endoscopic polypectomy have been enrolled since June 2010. They were then randomized into two groups as follows: supplementation group (0.9 g GTE per day for 12 months) or control group without GTE supplementation. Follow-up colonoscopy was conducted in 12 months. A structured 72-h recall at baseline and the 1-year follow-up was used to assess dietary factors, and to evaluate rectal mucosal proliferation index (RMPI) using known proliferation markers (Ki-67/PCNA), at least 2 random biopsies of rectal mucosa were taken. A sample size of 176 patients (88 per each group) was calculated to give the study 80% power to detect a difference, assuming a two-sided significance test at the 0.05 level.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 176 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Green Tea Extracts for the Prevention of Colorectal Adenomas and Colorectal Cancer
Study Start Date : August 2010
Actual Primary Completion Date : May 2015
Actual Study Completion Date : October 2015

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
No Intervention: Control
Without green tea extract (GTE) supplementation
Experimental: GTE group
GTE supplementation for 12 months after polypectomy for colorectal adenomatous polyps
Dietary Supplement: GTE (green tea extract)
6 GTE tablets per day. Daily dose is equivalent of 9 cup-of-green tea per day (0.9 g/day GTE, 0.6 g/day epigallocatechin gallate [EGCG]).

Primary Outcome Measures :
  1. Recurrence/Number/Size of metachronous colorectal adenoma(s) [ Time Frame: 1 year ]

Secondary Outcome Measures :
  1. Recurrence/Number/Size of metachronous colorectal polyp(s) including hyperplastic polyp(s) [ Time Frame: 1 year ]
  2. Change of lipid profiles after green tea extract (GTE) supplementation [ Time Frame: 1 year ]
  3. Change of body weight, BMI and waist circumference [ Time Frame: 1 year ]
  4. Adverse effect(s) of GTE supplementation [ Time Frame: every 1-3 months till the end of study protocol (12 months) ]

Information from the National Library of Medicine

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Ages Eligible for Study:   19 Years to 85 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

- subjects who present one or more adenomatous polyps on colonoscopy.

Exclusion Criteria:

  • subjects who denied to participate in this study
  • subjects who present inflammatory bowel diseases such as ulcerative colitis or crohn's disease
  • subjects who received partial or total colectomy due to colon cancer or other colonic diseases.
  • subjects who are pregnant
  • subjects who are on aspirin or NSAIDS for any reasons
  • subjects who have received a transplant of any major organ or who are on immunosuppressants for any reason
  • subjects who are unable to perform a bowel prep or who present poor bowel prep for colonoscopy

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02321969

Sponsors and Collaborators
Seoul National University Hospital
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Principal Investigator: Dong Ho Lee, M.D., Ph.D. Seoul National Universtiy Bundang Hospital
Publications of Results:
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Seoul National University Hospital Identifier: NCT02321969    
Other Study ID Numbers: B-1006/103-002
First Posted: December 22, 2014    Key Record Dates
Last Update Posted: October 28, 2015
Last Verified: October 2015
Keywords provided by Seoul National University Hospital:
Colorectal adenomatous polyp
Green tea extract
Additional relevant MeSH terms:
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Colorectal Neoplasms
Intestinal Neoplasms
Gastrointestinal Neoplasms
Digestive System Neoplasms
Neoplasms by Site
Digestive System Diseases
Gastrointestinal Diseases
Colonic Diseases
Intestinal Diseases
Rectal Diseases
Neoplasms, Glandular and Epithelial
Neoplasms by Histologic Type