Approach to systemic therapy in early, hormone receptor-positive, HER2-negative breast cancer

HER2: human epidermal growth factor receptor 2; BRCA: breast cancer susceptibility genes; CPS: clinical and pathologic stage; EG: histologic grade; RS: recurrence score; EP: EndoPredict; PAM50: Predictory Analysis of Microarray 50; MammaPrint: Amsterdam 70-gene profile.
* High-risk criteria for hormone receptor-positive cancers, according to the OlympiA trial:^[1]

• If treated with adjuvant chemotherapy, patients were required to have >3 pathologically confirmed positive lymph nodes.
• If treated with neoadjuvant chemotherapy, patients were required to not have experienced a pathologic complete response, and to have a CPS+EG score of 3 or higher.^[2] The CPS+EG scoring system estimates relapse probability on the basis of clinical and pathologic stage (CPS) and estrogen receptor status and histologic grade (EG); scores range from 0 to 6, with higher scores indicating worse prognosis. The CPS+EG calculator is available online at www3.mdanderson.org/app/medcalc/index.cfm?pagename=bcnt.

¶ Among the gene expression profiles, the Oncotype DX 21-gene RS is the most well validated. Others include EP, PAM50, Breast Cancer Index, and MammaPrint.