Updated Framework Guides Assessment of Actionable Cancer Biomarkers

Broader use of tumor sequencing has expanded the volume and diversity of biomarker data available to oncologists, while also making interpretation more complex. In particular, clinicians must distinguish alterations that predict treatment benefit from those associated with resistance. In response to this growing complexity, researchers have developed an updated framework for ranking molecular alterations in precision oncology.

The European Society for Medical Oncology (ESMO) has published version 2 of the ESMO Scale for Clinical Actionability of molecular Targets (ESCAT v2). The framework is designed to help oncologists assess the clinical relevance of molecular alterations and match patients with appropriate targeted therapies. First introduced in 2018, ESCAT provided a common language for ranking genomic alterations according to the strength of evidence supporting their use in precision oncology.

ESCAT v2 retains the original scale’s core principles while adding refinements intended to improve clarity and consistency. The updated framework restructures Tier I to distinguish between different levels of certainty supporting a biomarker-treatment match while maintaining the same clinical recommendation for use. It also incorporates formal criteria for evaluating tumor-agnostic therapies through alignment with ESMO’s Tumor-Agnostic Classifier and Screener.

The framework provides more granular guidance on the use of prospective and real-world evidence and refines lower tiers to reflect current evidence-generation pathways. ESCAT v2 also introduces a parallel resistance scale for classifying biomarkers associated with reduced or absent treatment benefit. The new scale was developed independently of regulatory approvals and is intended to support therapeutic sequencing and treatment selection.

ESCAT v2 was published in Annals of Oncology on October 21, 2026. The updated framework is intended for integration into molecular diagnostic reports, molecular tumor board discussions, clinical practice guidelines, and routine treatment planning. ESMO states that the framework supports more consistent application of precision medicine across health care systems.

“Precision oncology has matured considerably since the original ESCAT was published. Clinicians today are faced with a far greater volume and diversity of biomarker information than ever before. ESCAT v2 provides a more nuanced and practical framework for interpreting both actionability and resistance biomarkers, helping translate increasingly complex molecular data into treatment decisions that benefit patients,” said Dr. Aya El Helali, first author of the Annals of Oncology paper.

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European Society for Medical Oncology