Green Tea and Reduction of Breast Cancer Risk

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.

Timeline

Start

2009-07

Primary completion

2014-06

Completion

2014-06

Publications

• Bathgate JR, Radler DR, Kurzer M, Samavat H. Green tea extract supplementation does not modify plasma concentration of F2-isoprostanes in women who are postmenopause: Findings from a randomized controlled trial. Nutr Res. 2023 May;113:29-38. doi: 10.1016/j.nutres.2023.03.001. Epub 2023 Mar 9.
• 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 F2-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. doi: 10.3945/ajcn.116.137075. 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.

Drugs

Indications