A Window of Opportunity Study of Pre-operative Endocrine Therapy With and Without Prometrium in Postmenopausal Women With Early Stage Breast Hormone Receptor Positive (HR+) Human Epidermal Receptor 2 Negative (HER2-) Breast Cancer.
Status: RECRUITING
Study type: INTERVENTIONAL
Conditions: Early-stage Breast Cancer|Hormone Receptor Positive Tumor
Interventions: DRUG: Letrozole|DRUG: Letrozole and Prometrium|DRUG: Tamoxifen and Prometrium
Sponsor: St Vincent's Hospital