Green tea catechins for chemoprevention of prostate cancer in patients with histologically-proven HG-PIN or ASAP. Concise review and meta-analysis

Abstract

A focused, single outcome meta-analysis on the protective role of extracts of green tea catechins against prostate cancer. Randomized, placebo-controlled studies enrolling patients with a histologically confirmed diagnosis of high-grade Prostate Intraepithelial Neoplasia or Atypical Small Acinar proliferation but no prostate cancer were included. Meta-analysis for binary data was performed using Mantel-Haenszel statistics, using a random-effects model. Heterogeneity was investigated by calculating the I2. Four studies matched the inclusion criteria for the review. The pooled population was 223 patients; 114 and 109 patients were randomized to catechin and placebo groups, respectively. Nine cases of prstate cancer occurred in the catechin arm (7.9%), and 24 cases were reported in the placebo arm (22%). Pooled analysis resulted in a significant reduction of cancer risk in favor of the catechin arm (risk-ratio = 0.41; 95% CI: 0.19- 0.86; I2 = 0). In conclusion, our data suggest that the intake of concentrated green tea catechin preparations may confer a significant protective effect to carriers of early neoplastic lesions in the prostate. The quality of the evidence is moderate, and additional, largescale studies are warranted to substantiate these preliminary findings.

Nutraceutical treatment and prevention of benign prostatic hyperplasia and prostate cancer

“…We deemed interesting to integrate such meta-analysis with the more recent studies of Lassed et al (280 patients, risk ratio = 0.51; 95% CI: 0.14-1.82) and Sen et al, (142,196 men, of which 7036 PCa cases; risk ratio: 1.06; 95% CI: 0.98-1.14) (148,149). Our metanalysis (Figure 1) (150) shows that, in contrast to the significant data of Fei and coworkers ( 147), (risk ratio = 0.84; 95% CI: 0.71-0.98), the addition of the Lassed and Sen (148,149) trials results in a non-significant pooled risk ratio (0.89; 95% CI: 0.77-1.02). The publication bias for this pooled analysis is not significant (Egger's test: p = 0.542; Begg&Mazumdar's test: p = 0.311), but the analysis shows substantial heterogeneity (I2 = 0.69).…”

Effects of Green Tea Catechins on Prostate Cancer Chemoprevention: The Role of the Gut Microbiome

“…The objective of this review is to summarize the current research on the safety and effectiveness of GTCs in modulating prostate carcinogenesis based on population, in vitro, pre-clinical and early clinical trials. Although previous reviews have examined the pre-clinical and early phase trials of GTCs and PCa [ 29 , 30 , 31 , 32 , 33 ], our review will additionally identify discrepancies in the results of previous studies and examine the early and evolving data on the role of the gut microbiome in modulating the bioavailability, safety, and anticarcinogenic properties of GTCs in prostate carcinogenesis.…”

Stiffening of Cancer Cell Membranes Is a Key Biophysical Mechanism of Primary and Tertiary Cancer Prevention with Green Tea Polyphenols

“…17) Furthermore, several phase II clinical trials with GTE indicated its preventive effects toward cancer development for patients with preneoplastic diseases in the prostate and oral cavity. [18][19][20] All results indicated that "Primary cancer prevention" for the general population can be achieved by drinking 10 cups of green tea/d to delay cancer onset (Fig. 2).…”