Review on FRench Evidence-based National Chemotherapy Treatment decision in early breast cancer using multigene assays: FRENCH-Touch project

Background Multigene assays (MGAs) are central to adjuvant chemotherapy (CT) decision making in hormone receptor (HR)-positive-positive/human epidermal growth factor receptor 2 (HER2)-negative early breast cancer (eBC). Clinical validity has been established in pivotal trials; however, implementation in routine practice remains incompletely characterized. In France, adoption occurred within specific temporary funding, contributing to heterogeneous access. Design Targeted narrative literature review of French observational studies from 2012 to 2025. Studies evaluating Oncotype DX®, MammaPrint®, EndoPredict®, or Prosigna® tests in HR-positive/HER2-negative eBC were eligible if they reported treatment decision and/or survival outcomes. Results Thirteen French observational studies were identified, including >9000 patients. CT de-escalation was the predominant clinical effect of MGA testing. Absolute changes in CT recommendations ranged from 17.5% to >70%, depending on assay, population, and study design, and de-escalation was highest in low genomic risk groups. Across assays, absolute changes in CT rate at the population level ranged from 17.5% to 45.4%, although denominators varied across studies. When reported, concordance between post-test recommendations and administered treatments exceeded 90%, supporting implementation of MGA-informed decisions in routine practice. FREDO-ODX, the main French observational study reporting survival endpoints, showed a 4-year invasive disease-free survival rate of 89.7%, consistent with benchmark trial data. French findings were aligned with international datasets. Conclusions French real-world data support the clinical relevance of MGAs in routine care, through CT de-escalation in clinically uncertain situations, with high implementation of post-test recommendations. These data are consistent with randomized trials and international real-world evidence and highlight the importance of equitable, sustainable access to testing in France.