mCODE (Minimal Common Oncology Data Elements)

mCODE is built entirely on the HL7 FHIR (Fast Healthcare Interoperability Resources) standard, using modern RESTful APIs and web technologies. This ensures seamless integration with existing Electronic Health Records (EHRs) and other FHIR-compliant systems.

• Uses standard FHIR Resources like Patient, Condition, Observation, and Procedure
• Defines specific FHIR Profiles that constrain these resources for oncology use cases
• Enables plug-and-play interoperability across different vendor systems

mCODE organizes essential oncology data into six foundational domains, each representing a critical aspect of a patient's cancer journey. These domains were selected by a multidisciplinary expert panel as the minimal set necessary for care and research.

• Patient: Demographics and baseline characteristics
• Disease: Primary cancer diagnosis, staging, and histology
• Genomics: Somatic mutations, biomarkers, and genomic reports
• Treatment: Medications, surgeries, and radiation therapy
• Outcome: Survival status, disease progression, and performance status
• Assessment: Cancer staging evaluations and tumor marker tests

mCODE is developed and maintained through an open, multi-stakeholder governance process led by the American Society of Clinical Oncology (ASCO) and the MITRE Corporation. This ensures the standard reflects real-world clinical needs rather than any single vendor's priorities.

• Governed by an Executive Committee with representatives from oncology, informatics, and patient advocacy
• All development occurs in public GitHub repositories with community input
• Regular balloting and comment periods ensure transparency and clinical validity

A primary goal of mCODE is to transform unstructured clinical data trapped in EHR narrative text into structured, computable data suitable for research. By standardizing data elements, mCODE enables:

• Pragmatic clinical trials using real-world evidence
• Cohort discovery for identifying eligible patients across institutions
• Quality reporting for value-based care programs
• Federated learning by providing a common data schema across sites without requiring centralized data aggregation

While mCODE defines a minimal set of data elements, it is designed to be extended. Implementers can layer additional FHIR profiles on top of the mCODE base to capture specialty-specific or trial-specific data without breaking conformance.

• Uses FHIR's Extension mechanism for custom data elements
• Supports US Core profiles as a foundational layer
• Enables Implementation Guides (IGs) for specific cancer types or research protocols
• Maintains backward compatibility as extensions evolve

mCODE includes a dedicated Genomics Domain that standardizes how somatic mutations and biomarkers are represented, bridging the gap between molecular pathology and clinical oncology.

• Aligns with the Global Alliance for Genomics and Health (GA4GH) standards
• Uses FHIR's Observation resource with specific genomic profiles
• Captures gene studied, variant description, and clinical significance
• Enables structured reporting of next-generation sequencing (NGS) results for treatment decision support