On May 29, 2020 EORTC reported that the long-term results of the MINDACT (EORTC 10041/BIG3-04) study were presented today in the ASCO (Free ASCO Whitepaper) virtual meeting (Press release, EORTC, MAY 29, 2020, View Source [SID1234558776]). MINDACT tests the 70-gene signature MammaPrint to help identifying breast cancer patients who would do not need adjuvant chemotherapy . In 2016, the results of the primary endpoint (distant metastasis free survival (DMFS)) at 5 years median follow up were presented . Dr Fatima Cardoso, the principle investigator of the study, presented the updated results with 8.7 years of median follow-up, with more than 90% of patients followed for at least 5 years. 6693 patients were enrolled in the randomised MINDACT study between 2007-2011. The DMFS was assessed at 5 years for 644 clinical high and genomic low risk patients who were randomised to follow the genomic risk assessment and received no chemotherapy. In addition, a secondary analysis was conducted to evaluate DMFS and overall survival in the same population of clinical high and genomic low population depending on whether chemotherapy was administered or not.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

The present analysis confirms that MINDACT is a positive de-escalation study, as the primary DMFS endpoint at 5 years is continually met in clinical high and genomic low risk patients who receive no chemotherapy. The outcome of the "intention to treat" population are shown in the table below.

At 8 years, the estimated DMFS gain for chemotherapy administration in Clinical-High/Genomic-Low is 2.6% and must be balanced with the treatment’s harmful side effects.

A subgroup analyses was performed regarding the effect of chemotherapy per age group. This analysis showed that: a) omitting chemotherapy in Clinical-High/Genomic-Low postmenopausal women continues to be safe, (DMFS gain 0.2% ± 2.3%), and a fully preserved performance of MammaPrint to forego adjuvant chemotherapy is demonstrated; b) in premenopausal women the difference seen might be clinically relevant (DMFS gain 5% ± 2.8%); importantly, this effect may possibly be related to chemotherapy-induced ovarian function suppression.

"The present analysis clearly proves that chemotherapy can safely be avoided for postmenopausal women, classified as high risk of relapse by traditional clinico-pathological factors, but with a MammaPrint test of low risk, confirming the clinical utility of this genomic test, " said Dr Fatima Cardoso, Principal Investigator of the Study and Director of the Breast Unit at the Champalimaud Clinical Centre, Lisbon, Portugal.

Research Funding:
MINDACT was supported by grants from the European Commission Framework Programme VI (FP6-LSHC-CT-2004-503426, "TRANSBIG Network of Excellence"), the Breast Cancer Research Foundation, the U.S. National Cancer Institute, the European Breast Cancer Council-, Pharmaceutical/Biotech Company, U.S. National Institutes of Health

Session Type: Oral Abstract Session
Session Title: Breast Cancer—Local/Regional/Adjuvant
Track: Breast Cancer—Local/Regional/Adjuvant
Subtrack: Adjuvant Therapy
Abstract #: 506
Clinical Trial Registry Number: NCT00433589
Citation: J Clin Oncol 38: 2020 (suppl; abstr 506)
DOI: 10.1200/JCO.2020.38.15_suppl.506
Research support: Funding

MINDACT was supported by grants from the European Commission Framework Programme VI (FP6-LSHC-CT-2004-503426, "TRANSBIG Network of Excellence"), the Breast Cancer Research Foundation, Novartis, F. Hoffman La Roche, Sanofi-Aventis, Eli Lilly, Veridex, the U.S. National Cancer Institute, the European Breast Cancer Council-Breast Cancer Working Group (BCWG grant for the MINDACT biobank), the Jacqueline Seroussi Memorial Foundation (2006 JSMF award), Prix Mois du Cancer du Sein (2004 award), Susan G. Komen for the Cure (SG05-0922-02), Fondation Belge Contre le Cancer (SCIE 2005-27), Dutch Cancer Society (KWF), The Netherlands Genomics Initiative – Cancer Genomics Centre (2008-2012), Association Le Cancer du Sein, Parlons-en!, the Brussels Breast Cancer Walk-Run and the American Women’s Club of Brussels, NIF Trust, German Cancer Aid, the Grant Simpson Trust and Cancer Research UK, La Ligue Nationale Contre Le Cancer. This trial was also supported by the EORTC Cancer Research Fund. Whole genome analysis was provided in kind by Agendia.

Role of the funding sources

The funders had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication.

Acknowledgments

We are grateful to all patients and families who participated in this study.

We are grateful to the European Commission Sixth Framework Programme (FP6-LSHC-CT-2004-503426), the European Community Seventh Framework Programme (HEALTH-F2-2009-223175 to the Collaborative Oncological Gene-environment Study), the Breast International Group (BIG) AISBL, F. Hoffmann-La Roche, Novartis, Sanofi-Aventis, for supporting this independent EORTC Study.