Clinical trial NCT02321969: Green Tea Extracts for the Prevention of Colorectal Adenomas and Colorectal Cancer
Official title: Green Tea Extracts for the Prevention of Colorectal Adenomas and Colorectal Cancer
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Neoplasms, Colorectal
Keywords: Chemoprevention
Colorectal adenomatous polyp
Green tea extract
Lead sponsor: Seoul National University Hospital
Sponsor class: OTHER
First posted: 2014-12-22
Enrollment: 176
Sex: ALL
Minimum age (years): 19
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

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).

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.

Eligibility criteria: 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

Primary outcomes:
measure: Recurrence/Number/Size of metachronous colorectal adenoma(s)
timeFrame: 1 year
Secondary outcomes:
measure: Recurrence/Number/Size of metachronous colorectal polyp(s) including hyperplastic polyp(s)
timeFrame: 1 year
measure: Change of lipid profiles after green tea extract (GTE) supplementation
timeFrame: 1 year
measure: Change of body weight, BMI and waist circumference
timeFrame: 1 year
measure: Adverse effect(s) of GTE supplementation
timeFrame: every 1-3 months till the end of study protocol (12 months)
Other outcomes:
Locations:
Study officials:
affiliation: Seoul National Universtiy Bundang Hospital
name: Dong Ho Lee, M.D., Ph.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Shimizu M, Fukutomi Y, Ninomiya M, Nagura K, Kato T, Araki H, Suganuma M, Fujiki H, Moriwaki H. Green tea extracts for the prevention of metachronous colorectal adenomas: a pilot study. Cancer Epidemiol Biomarkers Prev. 2008 Nov;17(11):3020-5. doi: 10.1158/1055-9965.EPI-08-0528.
citation: Stingl JC, Ettrich T, Muche R, Wiedom M, Brockmoller J, Seeringer A, Seufferlein T. Protocol for minimizing the risk of metachronous adenomas of the colorectum with green tea extract (MIRACLE): a randomised controlled trial of green tea extract versus placebo for nutriprevention of metachronous colon adenomas in the elderly population. BMC Cancer. 2011 Aug 18;11:360. doi: 10.1186/1471-2407-11-360.
citation: Shin CM, Lee DH, Seo AY, Lee HJ, Kim SB, Son WC, Kim YK, Lee SJ, Park SH, Kim N, Park YS, Yoon H. Green tea extracts for the prevention of metachronous colorectal polyps among patients who underwent endoscopic removal of colorectal adenomas: A randomized clinical trial. Clin Nutr. 2018 Apr;37(2):452-458. doi: 10.1016/j.clnu.2017.01.014. Epub 2017 Jan 29.