ERBB2 and breast cancer: Four hundred ten consecutive patients were finally enrolled with exclusion criteria as follows: unknown immunohistochemical (IHC) results or indefinite human epidermal growth factor receptor-2 (HER-2) status, bilateral invasive BC or noninvasive BC, history of abnormal bone marrow function, history of chemotherapy without NCCN guidelines or insufficient course, taking neoadjuvant chemotherapy, and no history of blood routine test (BRT) during the second week after adjuvant chemotherapy.