ERBB2 and breast cancer: However, a more recent meta‐analysis including over 27,000 patients with early breast cancer, with over 5000 patients being HER2‐positive, demonstrated a significantly better EFS (HR 0.31; 95% PI: 0.24–0.39) for patients attaining a pCR in the entire group, with particularly strong associations noted for the HER2‐positive subgroup (HR 0.32; 0.21–0.47).11