Breast Cancer Evolution During Neoadjuvant Systemic Therapy

This study collects tumor and blood samples at multiple time points during pre-surgery (neoadjuvant) chemotherapy for breast cancer, to track how the cancer changes in response to treatment and improve future therapies. **You may be eligible if...** - You have been confirmed to have invasive breast cancer that has not spread to other organs - You are about to start neoadjuvant (pre-surgery) chemotherapy, targeted therapy, or immunotherapy — but have not started yet - If HER2-negative, you are suitable for taxane chemotherapy; if HER2-positive, you are suitable for anti-HER2 therapy - You are 18 or older **You may NOT be eligible if...** - Your breast cancer has already spread to other parts of the body at the time of diagnosis - You are receiving only hormonal (endocrine) therapy before surgery - You have psychological or social conditions that would prevent you from completing the study Talk to your doctor to see if this trial is right for you.