WSG PLAN B trial: Evaluating efficacy of anthracycline-free chemotherapy in primary HER2-negative breast cancer after molecular-based risk assessment according to Oncotype DX and uPA/PAI-1

TPS106^ Background: Anthracycline- and taxane-based adjuvant chemotherapy (CHT) is standard of care in N+ breast cancer (BC) and shown to be the most effective regimen in N- BC, but overtreatment remains a major problem in both groups. Although a retrospective meta-analysis suggested highest benefit of anthracyclines (vs. CMF) in HER2+ BC, patient groups with HER2- BC deriving anthracycline benefit still need to be defined prospectively. Modern gene signatures identify a substantial number of patients at low risk of recurrence currently misclassified by conventional prognostic factors. The WSG Plan B trial compares an anthracycline-containing CHT regimen (ECx4-Docx4), with an anthracycline-free taxane-based regimen (TCx6) in patients with HER2- BC. In order to assess whether molecular-based risk assessment may prevent overtreatment, Plan B incorporates the 21-Gene Recurrence Score (RS) as mandatory risk stratification in hormone-receptor (HR)+ patients with 0-3 involved lymph nodes. Recent data suggest th...