Digital Pathology Test Stratifies Recurrence Risk in Early Breast Cancer

In hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative early breast cancer, accurate recurrence-risk assessment helps guide treatment decisions. However, individual risks can vary substantially even among patients considered clinically high risk, complicating decisions about additional therapy. To refine risk assessment within this group, a newly evaluated digital slide-based test combines routine pathology images with clinicopathological data to provide prognostic classification.

Spotlight Medical’s (Paris, France) myStage Dx is a software-only in vitro diagnostic medical device that assesses recurrence risk in this patient population. It combines analysis of a digitized histopathology slide with routinely available clinicopathological data to generate a prognostic classification for qualified healthcare professionals. The device holds CE marking under the European Union In Vitro Diagnostic Medical Devices Regulation (EU-IVDR).

Its prognostic performance was assessed in an independent, blinded evaluation using data from 620 patients enrolled in PANTHER, an international randomized phase III trial comparing dose-dense with standard chemotherapy. myStage Dx predictions were generated without access to clinical outcomes. Researchers at Karolinska Institutet in Sweden then linked the predictions to patient outcomes and independently evaluated performance according to a prespecified protocol and statistical analysis plan. The findings build on earlier evidence from the CANTO and UNIRAD trial cohorts, published in the Journal of Clinical Oncology in 2025.

Within the clinically high-risk PANTHER population, myStage Dx distinguished two groups with different long-term outcomes. The Low Risk group accounted for 23.5% of patients, with an estimated 96.1% alive and free from breast cancer recurrence at ten years, compared with 76.6% in the Not Low Risk group. This difference remained statistically significant after adjustment for standard clinicopathological prognostic factors.

The PANTHER patients received chemotherapy and endocrine therapy without cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors. The results identify a subgroup with favorable long-term outcomes under those treatment conditions. Treatment discussions should consider individual recurrence risk, the expected benefits and risks of additional treatment, and patient preferences, consistent with American Society of Clinical Oncology (ASCO) guidance.

“Confidence in a clinical test has to be earned through independent scrutiny. We chose a blinded evaluation of myStage Dx by an independent research team, accepting that the results were outside our control. These findings are consistent with our previous studies and reinforce the test’s ability to address a concrete clinical problem: identifying patients with a favorable prognosis despite clinically high-risk disease, with a clear risk classification to inform treatment discussions,” said Dr. Marvin Lerousseau, co-founder and chief scientific officer of Spotlight Medical.

“As ASCO guidelines highlight, accurately assessing recurrence risk is essential to treatment decisions. For patients, additional therapies can mean up to three more years of treatment, with side effects, anxiety, and a real impact on daily life. We are proud to show how myStage Dx can help oncologists better assess individual risk and support more informed clinical decisions, with the aim of improving patient care,” said Sylvain Berlemont, co-founder and chief executive officer of Spotlight Medical.

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