Preclinical, epidemiological and prior clinical trial data suggest that green tea catechins (GTCs) may reduce prostate cancer (PCa) risk.
We conducted a placebo-controlled, randomized clinical trial of Polyphenon E® (PolyE), a proprietary mixture of GTCs, containing 400 mg (-)-epigallocatechin-3-gallate (EGCG) per day, in 97 men with high-grade prostatic intraepithelial neoplasia (HGPIN) and/or atypical small acinar proliferation (ASAP). The primary study endpoint was a comparison of the cumulative one-year PCa rates on the two study arms. No differences in the number of PCa cases were observed: 5/49 (PolyE) versus 9/48 (placebo), P=0.25. A secondary endpoint comparing the cumulative rate of PCa plus ASAP among men with HGPIN without ASAP at baseline, revealed a decrease in this composite endpoint: 3/26 (PolyE) versus 10/25 (placebo), P< 0.024. This finding was driven by a decrease in ASAP diagnoses on the Poly E (0/26) compared to the placebo arm (5/25). A decrease in serum prostate specific antigen (PSA) was observed on the PolyE arm [-0.87 ng/ml (95%CI: -1.66, -0.09)]. Adverse events related to the study agent did not significantly differ between the two study groups. Daily intake of a standardized, decaffeinated catechin mixture containing 400 mg EGCG per day for 1 year accumulated in plasma and was well tolerated but did not reduce the likelihood of PCa in men with baseline HGPIN or ASAP.
Kumar NB, Pow-Sang J, Egan KM, Spiess PE, Dickinson S, Salup R, Helal M, McLarty JW, Williams CR, Schreiber F Medical Oncology, Parnes HL, Sebti S, Kazi A, Kang L, Quinn GP, Smith T, Yue B, Diaz K, Chornokur G, Crocker T, Schell MJ Are you the author?
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Reference: Cancer Prev Res (Phila). 2015 Apr 14. pii: canprevres.0324.2014.