Efficacy of High Dose Tamoxifen to Advanced Hormone Receptor-High Expressed Breast Cancer

Background: Endocrine therapy is an effective and safe treatment for hormone receptor positive breast cancer. Unfortunately , endocrine treatment resistance occurs and there is an urgent need for treatment alternative. Laboratory researches and clinical case reports indicate that hormone receptor-high expressed breast cancer patients may potentially benefit from high-dose Tamoxifen or high-dose Tamoxifen plus chemotherapy , providing a new option for treatment strategy. Aim: To explore the efficacy and safety of high-dose Tamoxifen to standard hormone receptor-high expressed endocrine therapy resisted breast cancer. Methods: Eligible patients will be treated with tamoxifen 100 mg/d or high-dose Tamoxifen(100 mg/d ) plus chemotherapy. Blood and tumor samples will be obtained from the patients.Evaluate curative effect every 3 months. Primary endpoint: progression-free survival (PFS). Secondary endpoints: objective response rate (ORR), clinical benefit rate (CBR), overall survival (OS) and safety. Exploratory endpointsincluded the efficacy predictive value of the 18F-FES SUVmax.