Compare Continuation of Original Targeted Therapy With Trastuzumab Combined With Pyrotinib and Capecitabine as Postoperative Adjuvant Therapy in Non-pCR Patients With HER2 Positive Early Breast Cancer

This study compares two treatment approaches in women with HER2-positive early breast cancer who received chemotherapy before surgery but still had cancer remaining after surgery. It compares continuing the original targeted therapy versus switching to a combination of trastuzumab, pyrotinib, and capecitabine. **You may be eligible if...** - You are a woman aged 18–75 with early-stage breast cancer - Your cancer is HER2-positive (confirmed by biopsy) - You received at least 9 weeks of trastuzumab and taxane chemotherapy before surgery - You still had invasive cancer in your breast or lymph nodes after surgery - You are in good general health (ECOG 0–1) - Your hormone receptor status (ER and PR) is known **You may NOT be eligible if...** - You had a complete cancer response to pre-surgery chemotherapy (no cancer remaining) - You have metastatic (stage IV) breast cancer - You have significant heart, liver, or kidney problems - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.