Recommended Terms and Definitions From the 2025 NCCN Biomarkers Resource Committee

The NCCN Biomarkers Resource Committee (BRC) was established to provide molecular expertise and guidance related to key aspects of biomarker testing in NCCN publications. A key aim is to reduce inconsistencies and standardize biomarker testing terms and definitions for suggested use across all NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines). The key areas found to need terminology clarification and harmonization included those describing types of genomic events and testing approaches. For these areas, current professional society guidelines regarding terminology, utilization within current guidelines, and common parlance in practice were explored. Synonyms were also identified. Each area was discussed to nominate preferred (and, when applicable, nonpreferred) terminology with a rationale. The aims of this document are to define commonly used terms for clinical care providers and provide recommendations for the standardized use of this biomarker terminology within NCCN Guidelines and publications.