Fulvestrant or Capecitabine Combined With Pyrotinib in HR+/HER2+ Metastatic Breast Cancer

This trial tests combinations of targeted drugs (pyrotinib with either fulvestrant or capecitabine) in women with a specific type of metastatic breast cancer that is both hormone receptor-positive (HR+) and HER2-positive. **You may be eligible if...** - You are a woman aged 18–80 with metastatic breast cancer confirmed as HR+ and HER2+ - You are postmenopausal (or have had ovarian suppression if premenopausal) - You have received prior trastuzumab-based treatment - You have at least one measurable tumor - Your general health score (WHO performance status) is 0–2 - Your blood counts and organ function are within acceptable ranges **You may NOT be eligible if...** - You are male - You have not had prior trastuzumab treatment, or you have had more than one line of trastuzumab-based therapy for metastatic disease - Your cancer has not been confirmed as HR+ and HER2+ - Your health status is too poor to tolerate treatment Talk to your doctor to see if this trial is right for you.