Data from the FLEX Study demonstrate that MammaPrint High Risk 2, BluePrint Luminal B, is predictive of benefit from AC-T therapy, with a significantly higher 3-year IDFS rate than with TC therapy, alone.
• Higher 3-year IDFS for High Risk 2 patients treated with ACT-T than for TC-treated patients (89.3% vs 100%)
– At 4- and 5-years the absolute differences in IDFS for patients with High Risk 2 tumors were 8.1% and 13.7%, respectively, in favor of AC-T treatment.
– High Risk 2 patients may benefit from the addition of doxorubicin to taxane/cyclophosphamide therapy
• No significant different in 3-year IDFS rates for High Risk 1 patients treated with AC-T or TC (95.6% vs 94.6)
– Potential opportunity to avoid added toxicities of anthracycline in High Risk 1, Luminal B patients
O’Shaughnessy et al., SABCS 2025 #PS2-07-03
*Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Breast Cancer V.2.2026. © National Comprehensive Cancer Network, Inc. 2026. All rights reserved. Accessed March 16, 2026. To view the most recent and complete version of the guidelines, go online to NCCN.org. NCCN makes no warranties of a whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way. ^This information is presented for HCPs to use their clinical judgment.
