PTEN promoter methylation predicts 10-year prognosis after adjuvant tamoxifen for in HR-positive breast cancer

There is a need of biomarkers for endocrine resistance of hormone receptor-positive breast cancer. In vitro experiments have shown that downregulation of PTEN expression leads to resistance to tamoxifen in breast cancer cells. A study in West China Hospital of Sichuan University found that that low PTEN expression and high methylation of its promoter sequence -819 to -787 bp in breast cancer tissue predict poor DFS and OS in hormone receptor-positive early breast cancer patients who received adjuvant tamoxifen.