ERBB2 and breast cancer: The APT trial demonstrated that patients with tumor size ≤ 3.0 cm, node-negative HER2-positive breast cancer had a favorable 3-year invasive disease-free survival (iDFS) of 98.7% treated with weekly paclitaxel and trastuzumab, including 33.7% patients ≥ 60 years and 10.1% patients ≥ 70 years old 26.