A Randomized, Phase III Trial of Pre-Operative Window of Endocrine Therapy to Inform Radiation Therapy Decisions in Older Women With Early-Stage Breast Cancer (POWER II)

This is a Phase III, multisite exploratory study for women ≥ 65 years of age with early stage estrogen receptor positive (ER+) breast cancer. These individuals will be treated randomly assigned to one of two groups:

Intervention, treated with 3 months of pre-operative endocrine therapy (pre-ET) OR Control, participants follow standard of care and proceed directly to breast cancer surgery.

Both arms will be assessed for tolerance and compliance to the endocrine therapy by patient reported outcome (PRO) measures (patient surveys).