ERBB2 and neoplasm: In the primary tumor, HER2-positive tumors exhibit the highest complete response (CR) rate at 63.6% (n = 14/22), followed by triple-negative tumors at 38.5% (n = 10/26), Luminal B tumors at 25.9% (n = 22/85), and Luminal A tumors at 9.3% (n = 5/54).