ERBB2 and neoplasm: Therefore, AJCC 8th edition staging manual introduced the prognostic stage system (PS) by incorporating biomarkers including estrogen receptor (ER) and progesterone receptor (PR) expression, human epidermal growth factor receptor 2 (HER2) status, tumor grade, as well as multigene assays when available, with TNM classification, while maintaining the TNM-based anatomic stage system(AS) (6).