MammaPrint Test Addressed in ASCO Breast Cancer Guideline Update

For immediate release
July 10, 2017


Kate Crawford

ALEXANDRIA, Va – New recommendations on the use of the MammaPrint genomic test issued today will help guide decisions on adjuvant systemic therapy for women with early breast cancer. The recommendations update the American Society of Clinical Oncology (ASCO) 2016 clinical practice guideline on the use of biomarkers in these patients.

“Some women with breast cancer are more likely to have a recurrence of cancer and need to receive chemotherapy to lower this risk,” said Vered Stearns, MD, co-chair of the Expert Panel that developed the guideline update. “The MammaPrint test can now be added to the list of tests that help clinicians identify women who need chemotherapy and those who do not.”

This focused update was initiated following the 2016 publication of findings from the MINDACT randomized phase III clinical trial.1 The study explored the use of the MammaPrint 70-gene test to guide treatment decisions in more than 6,500 women with early-stage breast cancer.

“Certain women with a low-risk score on MammaPrint may not need chemotherapy and may be spared its side effects,” said Ian Krop, MD, PhD, co-chair of the Expert Panel that developed the guideline update. “However, this test is not suitable for all women with early breast cancer. For example, we do not recommend it for women with HER2-positive tumors or those with triple-negative breast tumors.”

Key recommendations of the guideline update:

  • The use of the MammaPrint assay can be considered to inform decisions on adjuvant systemic chemotherapy in women with estrogen receptor-positive or progesterone receptor-positive, HER2-negative, node-negative breast cancer who are at a high clinical risk of recurrence per MINDACT categorization (details provided in Data Supplement published with this guideline).
  • MammaPrint can also be considered in women with estrogen receptor-positive or progesterone receptor-positive, HER2-negative breast cancer with 1-3 positive lymph nodes who are at a high clinical risk of recurrence.
    • Women meeting either of these criteria whose MammaPrint score is low may be treated with hormone therapy alone, as it is unlikely that chemotherapy will provide substantial additional benefits.
  • MammaPrint should not be used in women who have a low clinical risk for recurrence per MINDACT categorization.

The Use of Biomarkers to Guide Decisions on Adjuvant Systemic Therapy for Women with Early-Stage Invasive Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline Focused Update was published today in the Journal of Clinical Oncology.

The guideline update is available at

Information for patients about breast cancer is available at

ASCO encourages feedback on its guidelines from oncologists, practitioners and patients through the ASCO Guidelines Wiki.

170-Gene Signature as an Aid to Treatment Decisions in Early-Stage Breast Cancer. N Engl J Med 2016; 375: 717-29.


About ASCO: 

Founded in 1964, the American Society of Clinical Oncology, Inc. (ASCO®) is committed to making a world of difference in cancer care. As the world’s leading organization of its kind, ASCO represents nearly 45,000 oncology professionals who care for people living with cancer. Through research, education, and promotion of the highest-quality patient care, ASCO works to conquer cancer and create a world where cancer is prevented or cured, and every survivor is healthy. ASCO is supported by its affiliate organization, the Conquer Cancer Foundation. Learn more at, explore patient education resources at www.Cancer.Net, and follow us on Facebook, Twitter, LinkedIn, and YouTube.