Evaluating Minimal Residual Disease (MRD) Through Longitudinal Circulating Tumor DNA (ctDNA) Profiling in Breast Malignancies

This study tracks tiny fragments of tumor DNA circulating in the blood (called ctDNA) over time in breast cancer patients. It aims to detect whether cancer is lingering after treatment even when standard scans look clear — helping identify who needs more aggressive therapy. **You may be eligible if...** - You have been diagnosed with breast cancer (any subtype) - You are willing to provide blood samples over time - For the high-risk HR+/HER2- group: you have Stage II–III disease with 4 or more positive lymph nodes, or 1–3 positive nodes plus grade 3 disease or a tumor 5 cm or larger - For the HER2+ group: Stage II–III disease treated with curative intent - For the triple-negative group: Stage II–III disease treated with curative intent **You may NOT be eligible if...** - You are not willing or able to provide blood samples - You are unable to provide informed consent Talk to your doctor to see if this trial is right for you.