Stage a cancer patient using mCODE TNM staging profiles: TNMStageGroup and category observations

In-depth guide

Steps

1. Create a TNMStageGroup Observation (profile: mcode-tnm-stage-group): set Observation.code to a LOINC staging code — clinical (21908-9), pathologic (21902-2), or other (21914-7) — matching the staging method used
2. Set Observation.valueCodeableConcept to the overall stage group (e.g., AJCC Stage IIB) using codes from the AJCC stage group value set bound by the IG
3. Set Observation.method to a CodeableConcept identifying the staging system version (e.g., AJCC 8th edition); this is critical for reproducibility
4. Create the T, N, and M category Observations (mcode-tnm-primary-tumor-category, mcode-tnm-regional-nodes-category, mcode-tnm-distant-metastases-category) each with their appropriate LOINC code and AJCC category value
5. Link the category Observations to the TNMStageGroup Observation using Observation.hasMember references so the stage group bundles all component categories
6. Set Observation.subject to the cancer patient and Observation.focus to the PrimaryCancerCondition to establish the clinical context for the staging