Early breast cancer: ASCO adds MammaPrint to guideline

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Takeaway

  • The MammaPrint genomic assay is best used to guide systemic therapy decisions in 2 groups of patients with early breast cancer: 1) hormone receptor (HR)-positive/human epidermal growth factor receptor (HER2)-negative, node-negative patients with high clinical risk; and 2) HR+/HER2−, node-positive patients with high clinical risk, according to a new clinical practice guideline by the American Society of Clinical Oncology (ASCO).
  • Most other groups of patients do not benefit from MammaPrint.

Why this matters

  • A patient with a favorable score on MammaPrint may skip chemotherapy.

Study design

  • An expert panel reviewed the phase 3 MINDACT study of 6693 women, which was published after ASCO's previous clinical practice guideline of February 2016.
  • Funding: None disclosed.

Key recommendations

  • MammaPrint should be used for HR+/HER2−, node-negative as well as node-positive (1-3 nodes) patients with high clinical risk.
  • MammaPrint is irrelevant for HR+/HER2−, node-negative patients with low clinical risk because they already do not benefit from chemotherapy.
  • MammaPrint should not be used for HR+/HER2−, node-positive patients with low clinical risk; HER2+ patients; and triple-negative breast cancer because of the absence of clinical data.