Journal Article

Green Tea Extract to Prevent Colorectal Adenomas, Results of a Randomized, Placebo-Controlled Clinical Trial

Rohlmann, Friederike, Seufferlein, Thomas, Behrens, Rüdiger, Zipprich, Alexander, Schneider, Katharina L., Metter, Klaus, Menzler, Stefan, Kleber, Gerhard, Berger, Andreas W., Heuer, Theodor, Messmann, Helmut, Odemar, Frank, Algül, Hana, Hügle, Ulrich, Frank-Gleich, Stefanie, Ettrich, Thomas J., Perkhofer, Lukas, Muche, Rainer, Stingl, Julia C., Scholl, Catharina

2022

Overview

Preclinical, epidemiological, and small clinical studies suggest that green tea extract (GTE) and its major active component epigallocatechingallate (EGCG) exhibit antineoplastic effects in the colorectum. A randomized, double-blind trial of GTE standardized to 150 mg of EGCG b.i.d. vs placebo over 3 years was conducted to prevent colorectal adenomas (n = 1,001 with colon adenomas enrolled, 40 German centers). Randomization (1:1, n = 879) was performed after a 4-week run-in with GTE for safety assessment. The primary end point was the presence of adenoma/colorectal cancer at the follow-up colonoscopy 3 years after randomization. The safety profile of GTE was favorable with no major differences in adverse events between the 2 well-balanced groups. Adenoma rate in the modified intention-to-treat set (all randomized participants [intention-to-treat population] and a follow-up colonoscopy 26-44 months after randomization; n = 632) was 55.7% in the placebo and 51.1% in the GTE groups. This 4.6% difference was not statistically significant (adjusted relative risk 0.905; P = 0.1613). The respective figures for the per-protocol population were 54.3% (151/278) in the placebo group and 48.3% (129/267) in the GTE group, indicating a slightly lower adenoma rate in the GTE group, which was not significant (adjusted relative risk 0.883; P = 0.1169). GTE was well tolerated, but there was no statistically significant difference in the adenoma rate between the GTE and the placebo groups in the whole study population.

• Publisher: Wolters Kluwer,Wolters Kluwer Health Medical Research, Lippincott Williams & Wilkins
• Subject: Adenoma - prevention & control / Antioxidants - therapeutic use / Aspirin / Cancer / Cell cycle / Colonoscopy / Colorectal cancer / Colorectal Neoplasms - prevention & control / DNA methylation / Double-Blind Method / Enzymes / Gastroenterology / Humans / Informed consent / Mutation / Nonsteroidal anti-inflammatory drugs / Plant Extracts - therapeutic use / Population / Prevention / Statistical analysis / Tea / Tumors