The Sleep After Breast Cancer (ABC) Study - Examining Sleep Changes and Biomarkers Among Breast Cancer Patients

This observational study is following women recently diagnosed with early-stage hormone receptor-positive breast cancer to understand how sleep quality and patterns change from before chemotherapy or radiation begins through the course of treatment. It also looks at biological markers that may be linked to sleep disruption. **You may be eligible if...** - You are 18 or older - You have been diagnosed with stage I–III hormone receptor-positive breast cancer - You have recently had surgery but have not yet started chemotherapy or radiation - There is no evidence of cancer spread or recurrence - You can speak, read, and understand English **You may NOT be eligible if...** - You have stage IV (metastatic) breast cancer - You have had another cancer diagnosis since your breast cancer diagnosis - You are not willing or not cognitively able to give informed consent Talk to your doctor to see if this trial is right for you.