Effects of a green tea extract, Polyphenon E, on systemic biomarkers of growth factor signalling in women with hormone receptor-negative breast cancer.

BACKGROUND: Observational and experimental data support a potential breast cancer chemopreventive effect of green tea. METHODS: We conducted an ancillary study using archived blood/urine from a phase IB randomised, placebo-controlled dose escalation trial of an oral green tea extract, Polyphenon E (Poly E), in breast cancer patients. Using an adaptive trial design, women with stage I-III breast cancer who completed adjuvant treatment were randomised to Poly E 400 mg (n = 16), 600 mg (n = 11) and 800 mg (n = 3) twice daily or matching placebo (n = 10) for 6 months. Blood and urine collection occurred at baseline, and at 2, 4 and 6 months. Biological endpoints included growth factor [serum hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF)], lipid (serum cholesterol, triglycerides), oxidative damage and inflammatory biomarkers. RESULTS: From July 2007-August 2009, 40 women were enrolled and 34 (26 Poly E, eight placebo) were evaluable for biomarker endpoints. At 2 months, the Poly E group (all dose levels combined) compared to placebo had a significant decrease in mean serum HGF levels (-12.7% versus +6.3%, P = 0.04). This trend persisted at 4 and 6 months but was no longer statistically significant. For the Poly E group, serum VEGF decreased by 11.5% at 2 months (P = 0.02) and 13.9% at 4 months (P = 0.05) but did not differ compared to placebo. At 2 months, there was a trend toward a decrease in serum cholesterol with Poly E (P = 0.08). No significant differences were observed for other biomarkers. CONCLUSIONS: Our findings suggest potential mechanistic actions of tea polyphenols in growth factor signalling, angiogenesis and lipid metabolism.

Breast cancer chemoprevention: current clinical practice and future direction.

With the unblinding of the Breast Cancer Prevention Trial (BCPT) in 1998, the clinical management of breast cancer prevention patients has expanded from the time-honored triad of breast cancer screening to include breast cancer risk assessment and risk reduction. With a proven 49% reduction in the incidence of breast cancer, tamoxifen is now the gold standard in chemoprevention for breast cancer risk reduction for women at increased risk of the disease. The suggested 74% reduction in the incidence of breast cancer seen with raloxifene in the Multiple Outcomes of Raloxifene Evaluation (MORE) trial is the basis of the now ongoing Study of Tamoxifen and Raloxifene (STAR) for the Prevention of Breast Cancer. Findings are anticipated in 2006.