ESCAT v2 helps oncologists interpret genomic alterations, assess actionability biomarkers and identify resistance biomarkers for precision cancer treatment

ESMO has published version 2 of the ESMO Scale for Clinical Actionability of molecular Targets (ESCAT), a major update to the internationally recognised precision oncology framework that helps oncologists assess the clinical relevance of molecular alterations and match patients with the most 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. Since then, the field has evolved dramatically, with broad adoption of tumour sequencing, the emergence of tumour-agnostic therapies, growing use of real-world evidence, and increasing recognition of biomarkers that predict resistance to treatment. These advances created the need for an updated framework that reflects contemporary clinical practice and supports confident decision-making.

Published in Annals of Oncology, ESCAT v2 retains the core principles that made the original scale widely adopted while introducing several important refinements designed to increase clarity, consistency, and ultimately patient benefit.

Among the most significant updates is the restructuring of Tier I, which now explicitly distinguishes between different levels of certainty supporting a biomarker-treatment match while maintaining the same clinical recommendation for use. The new framework also incorporates formal criteria for evaluating tumour-agnostic therapies through alignment with ESMO's Tumour-Agnostic Classifier and Screener (ETAC-S), provides more granular guidance on the use of prospective and real-world evidence, and refines the lower tiers to better reflect current evidence generation pathways.

Importantly, ESCAT v2 introduces what is believed to be the first systematic, evidence-based resistance scale developed independently of regulatory approvals. The new parallel framework enables clinicians to classify biomarkers associated with reduced or absent treatment benefit, supporting more informed therapeutic sequencing and treatment selection.

“Precision oncology has matured considerably since the original ESCAT was published,” said Dr Aya El Helali, first author of the paper published in Annals of Oncology[LINK]. “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,” she explained.

The updated framework is intended for integration into molecular diagnostic reports, molecular tumour board discussions, clinical practice guidelines, and everyday treatment planning. By providing a transparent, evidence-based assessment of biomarker relevance, ESCAT v2 supports oncologists in navigating the growing complexity of cancer care while fostering more consistent application of precision medicine across healthcare systems.

“One of ESMO's core responsibilities is to help oncology professionals keep pace with rapidly evolving science and translate evidence into better patient care,” said ESMO President Fabrice André, who was in the group who developed the first version of ESCAT. “ESCAT v2 exemplifies ESMO's commitment to developing practical frameworks and guidance that support clinicians in making informed decisions in an increasingly data-rich and complex oncology landscape,” he continued.

As outlined in the ESMO Roadmap 2030, supporting the effective implementation of precision oncology remains a strategic priority for the Society. ESCAT v2 represents another step towards ensuring that every patient undergoing molecular testing receives a clear, evidence-based interpretation of findings that can guide treatment decisions.

Read the full ESCAT v2 paper in Annals of Oncology and learn how the updated framework can support biomarker-guided treatment decisions in precision oncology.