MII IG Kerndatensatz-Modul Onkologie
2027.0.0-ballot.1 - Germany

This page is part of the MII IG Kerndatensatz-Modul Onkologie (v2027.0.0-ballot.1: Release) based on FHIR (HL7® FHIR® Standard) R4. This is the current published version in its permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions

TNM Breast Cancer Journey (Example)

Overview

This comprehensive example demonstrates the complete TNM staging journey of a breast cancer patient across five critical points in time. It illustrates the complexity of real-world oncological assessment and shows how the FHIR architecture, with linked Observations, represents clinical reality.

Graphical representation

TNM staging journey of a breast cancer patient across five points in time

The image is provided as .svg and can be opened and downloaded separately for a better view: TNM_Breast_Cancer_Journey.svg.

Clinical context

The patient passes through the following staging phases:

Point in time TNM stage Description UICC stage
January 2024 cT3N1M0 Initial clinical assessment Stage IIIA
February 2024 pT4cN1cM0 After biopsy - mixed assessment Stage IIIB
May 2024 ycT2ycN0cM0 After neoadjuvant chemotherapy Stage IIA
June 2024 ypT0ypN0cM0 After surgery - complete pathological remission Complete Response
June 2027 rcT2N1M1 Recurrence after 3 years disease-free interval Stage IV

Architecture highlights

1. Component reuse

The initial cM0 Observation (January 2024) is referenced in several later classifications:

  • In the mixed staging after biopsy (pT4cN1cM0)
  • After neoadjuvant therapy (ycT2ycN0cM0)
  • In the postoperative assessment (ypT0ypN0cM0)

This shows that not all TNM categories need to be reassessed at every staging phase.

2. Mixed assessment types

The example pT4cN1cM0 demonstrates a common clinical situation:

  • T category: assessed pathologically by biopsy (pT4)
  • N category: assessed clinically by imaging (cN1)
  • M category: assessed clinically by CT scan (cM0)

3. Use of prefixes

Category-level prefixes (c/p):

  • Applied to individual TNM components
  • Indicate the assessment method (clinical vs. pathological)

Classification-level prefixes (y/r):

  • y: post-neoadjuvant therapy assessment
  • r: recurrence staging after a disease-free interval

SNOMED CT coding

Each TNM category carries two codings:

  1. UICC code: the traditional TNM value (e.g. T3, N1, M0)
  2. SNOMED CT code: specific code from the UICC qualifier value hierarchy

Example for cT3:

* valueCodeableConcept = $UICC#T3 "T3"
* valueCodeableConcept.coding[+] = $SCT#1352966002 "Union for International Cancer Control cT3 (qualifier value)"

Implementation notes

Observation.hasMember architecture

Using hasMember instead of component allows:

  • Temporal coherence: each category keeps its own effectiveDateTime
  • Method tracking: different assessment methods per category
  • Reusability: Observations, once created, can be referenced multiple times
  • Audit trail: complete history of who assessed what, when and how

Why not Observation.component?

Components cannot:

  • Have different assessment dates
  • Be reused across Observations
  • Have their own performers or methods
  • Represent the complex reality of mixed assessments

Technical details

Profiles used

Extensions

Example instances

The five staging time points are shipped as separate example instances; the structure view is found on the respective artefact page:

JSON representation

The full JSON and XML representation is available on each instance's artefact page:

Clinical validation

This example structure was developed to represent the following clinical realities:

  • Biopsy upgrades: only the T category is reassessed pathologically
  • Neoadjuvant response: complete reassessment with the y prefix
  • Pathological complete remission: ypT0ypN0 indicates a complete response
  • Distant metastasis assessment: the M category often remains clinical, since distant metastases are rarely biopsied
  • Recurrence documentation: new baseline with the r prefix after a disease-free interval

References

Usage notes for implementers

  1. Create TNM components only on reassessment: reuse existing Observations when no new assessment has taken place
  2. Use correct SNOMED codes: the ConceptMaps mii-cm-onko-tnm-uicc-sct-clinical and mii-cm-onko-tnm-uicc-sct-pathological contain all mappings
  3. Document the temporal context: the effectiveDateTime of each component should reflect the actual time of assessment
  4. Observe the prefix hierarchy: y/r prefixes apply to the entire classification, c/p prefixes to individual categories

Summary

This example demonstrates the full flexibility and expressiveness of the MII Onkologie TNM profiles. It shows how the FHIR architecture can precisely represent the complex reality of oncological staging processes while at the same time ensuring data integrity and reusability.