MINDACT poster session at ASCO annual meeting 2017

Intro text: 

ASCO ANNUAL MEETING – June 2-6, 2017 (Chicago, USA)

On 4 June 2017, the MINDACT study presented the chemotherapy randomisation results at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.* 

MINDACT (‘Microarray In Node negative and 1 to 3 positive lymph node Disease may Avoid ChemoTherapy’) is an international, prospective, randomised, phase III study to evaluate the added value of the 70 gene test (MammaPrint®) to the traditional method of assessing the likelihood of breast cancer recurrence for women with node-negative or 1-to-3 node positive breast cancer. MINDACT’s first results, published in the New England Journal of Medicine in August 2016, showed that potentially almost half of patients with this kind of breast cancer could be spared chemotherapy in the future.

During a poster discussion session at ASCO, Dr. Fatima Cardoso (Breast Unit, Champalimaud Clinical Centre/Champalimaud Foundation, Lisbon, Portugal), Chair of the EORTC (European Organisation for Research and Treatment of Cancer) Breast Cancer Group (member of BIG), Study Chair of the MINDACT trial, presented results of the chemotherapy randomisation that was part of the MINDACT study. 


Fatima Cardoso et al. analysed the group of patients within the trial for whom chemotherapy was decided and who agreed to participate in an optional part of MINDACT aiming to compare two chemotherapy types:  patients were randomly assigned to receive either standard anthracycline-based chemotherapy with or without taxanes (AT) or an experimental one without anthracyclines, using docetaxel plus capecitabine (DC). The study found that in all study endpoints, DC did not improve patient outcomes compared to AT, including those patients who were in the concordant group of clinical high risk (C-high)/genomic high risk (G-high, MammaPrint tested).

The aim of this randomisation was to prove the superiority of DC over anthracycline-based chemotherapy, which did not happen. Therefore, anthracyclines with or without taxanes remain the standard of care for early breast cancer, including those at the highest risk of relapse.

The MINDACT trial: from 2007 to 2011, doctors at 112 centres in nine countries enrolled in the trial 6,693 patients (out of 11,288 women screened) who had undergone surgery for early-stage breast cancer. All participants were categorised as low or high risk for tumour recurrence in two ways: first, through the genomic analysis of tumour tissue using MammaPrint (= innovative method, genomic test) by Agendia; and second, using a modified version of Adjuvant! Online, a tool that calculates the risk of breast cancer recurrence based on common clinical and biological criteria (= traditional method, clinical test). The participants were then divided into different groups: when both the genomic and the clinical tests showed high risk (G High/C High), the patients were recommended chemotherapy. When both tests showed low risk, no chemotherapy was proposed. When the two tests disagreed, patients were randomly assigned to follow the advice provided by one of the two tests.

MINDACT’s primary results published in 2016 demonstrated that the use of this genomic test can potentially reduce adjuvant chemotherapy of breast cancer patients by 46%, even in the presence of high risk clinical features. This means that nearly half of the early-stage breast cancer patients identified as high risk for recurrence based on traditional factors were identified as low risk when using the MammaPrint test. The data demonstrated that chemotherapy provided no clinically meaningful benefit for these patients.

Future research using the study’s biological sample collection can also contribute to a much deeper understanding of breast cancer and how to continue to improve treatment in the future.


* Cardoso F, et al. Standard anthracycline-based vs. docetaxel-capecitabine in early breast cancer: Results from the chemotherapy randomisation (R-C) of EORTC 10041/ BIG 3-04 MINDACT phase III trial. Poster presented at ASCO Annual Meeting. June 2017; Chicago, Illinois.