Pyrotinib Plus Capecitabine for Adjuvant Treatment of HER2 Positive Early-stage Breast Cancer

This study is testing whether pyrotinib combined with capecitabine (a chemotherapy pill) helps prevent HER2-positive early-stage breast cancer from coming back after surgery, for patients who still have cancer remaining after their initial chemotherapy before surgery. **You may be eligible if...** - You are a woman between 18 and 75 years old - You have been diagnosed with HER2-positive breast cancer and have had surgery (mastectomy or breast-conserving surgery) within the past 90 days - Your lymph nodes were positive, or you had a tumor larger than 1 cm (or 0.5–1 cm with additional high-risk features) - You are in good physical health **You may NOT be eligible if...** - Your cancer has come back or spread to other parts of the body - You have previously been treated with other HER2-targeted oral drugs (like lapatinib, neratinib, or pyrotinib) - You have been diagnosed with another cancer in the past 5 years (except certain skin or cervical cancers) - You have been in another clinical trial in the past 4 weeks Talk to your doctor to see if this trial is right for you.