Predicting Response to Neoadjuvant Endocrine Therapy (Neo-PREDICT)
The goal of this clinical trial is to determine how the duration of hormone blocking (endocrine) therapy given prior to surgery (called neoadjuvant treatment) affects breast cancer. The main questions the trial aims is answer are: 1. How breast cancer responds to endocrine therapy given prior to surgery? 2. To predict tumor pre-operative endocrine prognostic index (PEPI) score for subjects enrolled in cohort B or C Participants with early-stage breast cancer (Stage I-III) who are eligible for Neoadjuvant Endocrine Therapy (NET) will be enrolled in the study. Participants will: * receive endocrine therapy as part of regular care for breast cancer * consent to samples of blood and tissue evaluation to determine how endocrine therapy effects the tumor * participate in this research anywhere from 2 weeks to 1 year, depending on duration of endocrine therapy and when surgery will be performed
• Be capable of understanding the investigational nature of the study and all pertinent aspects of the study
• Be capable of signing and providing written consent in accordance with institutional and federal guidelines
• Histologically or cytologically confirmed diagnosis of invasive carcinoma of the breast
• Clinical stage 1 to 3 breast cancer
• Candidate for surgical resection
• Estrogen receptor \> 10% positive stained cells based on most recent tumor biopsy and documented by a local laboratory or medical record.
• HER2 negative or HER2 low breast cancer based on the most recent tumor biopsy and documented by a local laboratory or medical record. HER2 negative tumor is defined per American Society of Clinical Oncology and the College of American Pathologists guidelines, 2018. Patients with HER2 low tumors are eligible as long as patients are not candidates for any HER2 directed therapy.
• Ability to take oral medication
• Be willing and able to comply with scheduled visits, treatment plan, and follow up with research staff
• Age ≥ 21 years