Transferring MINDACT to Daily Routine: Implementation of the 70-Gene Signature in Luminal Early Breast Cancer - Results from a Prospective Registry of the Austrian Group Medical Tumor Therapy (AGMT)

Theresa Westphal; Simon P Gampenrieder; Gabriel Rinnerthaler; Marija Balic; Florian Posch; Nadia Dandachi; Cornelia Hauser-Kronberger; Roland Reitsamer; Karl Sotlar; Bianca Radl; Christoph Suppan; Herbert Stöger; Richard Greil

doi:10.1159/000512467

Transferring MINDACT to Daily Routine: Implementation of the 70-Gene Signature in Luminal Early Breast Cancer - Results from a Prospective Registry of the Austrian Group Medical Tumor Therapy (AGMT)

Breast Care (Basel). 2022 Feb;17(1):1-9. doi: 10.1159/000512467. Epub 2021 Mar 30.

Authors

Theresa Westphal^{1

2}, Simon P Gampenrieder^{1

2

3}, Gabriel Rinnerthaler^{1

2

3}, Marija Balic⁴, Florian Posch⁴, Nadia Dandachi⁴, Cornelia Hauser-Kronberger⁵, Roland Reitsamer⁶, Karl Sotlar⁵, Bianca Radl^{1

2}, Christoph Suppan⁴, Herbert Stöger⁴, Richard Greil^{1

2

3}

Affiliations

¹ IIIrd Medical Department with Hematology and Medical Oncology, Oncologic Center, Paracelsus Medical University Salzburg, Salzburg, Austria.
² Salzburg Cancer Research Institute with Laboratory of Immunological and Molecular Cancer Research and Center for Clinical Cancer and Immunology Trials, Salzburg, Austria.
³ Cancer Cluster Salzburg, Salzburg, Austria.
⁴ Division of Oncology, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
⁵ Pathologic Institute of the University Hospital Salzburg, Paracelsus Medical University Salzburg, Salzburg, Austria.
⁶ University Clinic for Special Gynecology of the University Hospital Salzburg, Paracelsus Medical University Salzburg, Salzburg, Austria.

Abstract

Background: For hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative early breast cancer (EBC), adjuvant chemotherapy (ACT) is recommended in the case of high-risk features only. The MINDACT trial showed that patients with high clinical risk (CR) but low genomic risk (GR) defined by the 70-gene signature (MammaPrint®; 70-GS) did not benefit from ACT. In this registry, we investigated the frequency and feasibility of 70-GS and concurrent 80-gene subtyping (BluePrint®) use in HR-positive, HER2-negative EBC. Furthermore, we recorded the frequency of ACT recommendation and the adherence to it when the "MINDACT strategy" was used.

Methods: This prospective registry included patients from 2 Austrian cancer centers. Similar to MINDACT, a modified version of Adjuvant!Online was used to determine CR, and 70-GC was used to determine GR in high-CR patients. ACT was recommended to patients with high CR and high GR.

Results: Of 224 enrolled patients, 76 (33.9%) had high CR and 67 (88.2%) received genomic testing. Of those, 43 (64.2%) were classified as low and 24 (35.8%) as high GR, respectively. All 24 patients with high CR and GR (10.7% of all patients) received the recommendation for ACT, but ACT was started in only 15 patients (62.5%). The median time from surgery to the start of ACT was 45 days (range 32-68), and the median time from test decision to the test result was 15 days (range 9-56).

Conclusion: We showed that the results of the MINDACT trial are reproducible in an Austrian population. Incorporating 70-GS into the daily clinical routine is feasible and mostly accepted by physicians for the guidance of treatment recommendations.

Keywords: 70-Gene signature; Adjuvant chemotherapy; Adjuvant!Online; Gene expression assay; Genomic testing; MammaPrint.