ERBB2 and breast cancer: However, those studies concluded that younger age at diagnosis had more frequent association with clinicopathologic features and gene expression for worse prognosis, including lower ER positivity, larger tumors, higher ERBB2 overexpression, lymph node positivity, and higher-grade tumors.17,18,19 Unlike previous studies, this study focused on ER-positive, ERBB2-negative subtypes among young patients with breast cancer and analyzed the risk of late DR in patients without DR within 5 years after surgery.