Trastuzumab Deruxtecan Alone or in Combination With Anastrozole for the Treatment of Early Stage HER2 Low, Hormone Receptor Positive Breast Cancer

This study tests whether a targeted drug called trastuzumab deruxtecan — alone or combined with a hormone-blocking drug (anastrozole) — can shrink breast tumors before surgery in women with early-stage, hormone-sensitive, HER2-low breast cancer. **You may be eligible if...** - You have early-stage invasive breast cancer larger than 2 cm - Your tumor is HER2-low (a specific low level of the HER2 protein) and hormone receptor-positive - You have not yet been treated for this breast cancer - You have good heart function (ejection fraction 50% or higher) - You are in good general health **You may NOT be eligible if...** - Your tumor is HER2-negative (zero expression) or HER2-positive (high expression) - Your cancer has spread beyond the breast to distant parts of the body - You have significant heart, lung, or other organ problems - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.