This study demonstrated that very young women (age group ≤35 years) with breast cancer had more higher-grade tumors, more probability of LVI in tumor, and more triple-negative subtype and received more lumpectomy, more chemotherapy especially more anthracycline- and paclitaxel-based chemotherapy, and more endocrine therapy plus OFS, anti-HER2 therapy, and adjuvant radiotherapy when compared with older patients. This evidence concerns the gene ERBB2 and breast cancer.