HL7 Europe Common Cancer Model, published by HL7 Europe. This guide is not an authorized publication; it is the continuous build for version 0.1.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/hl7-eu/cancer-common/ and changes regularly. See the Directory of published versions
A patient’s cancer journey is a longitudinal sequence of events that starts with presentation and evidence gathering, continues through condition assertion and staging, proceeds to treatment (often in overlapping episodes), and is followed by ongoing assessment of response and disease status. Capturing dates consistently for each step is essential so the timeline can be accurately reconstructed for care and research.
Text generated from the picture: to be checked
Figure 1: the typical cancer journey (part 1)
Figure 2: the typical cancer journey (part 2)
Foundations
Patient & Demographics
The journey is anchored to the Patient, including demographics (e.g., sex, birth date/year) and Comorbidities. Demographics and comorbidities may change over time and should be versioned accordingly.
Presentation & Early Evidence
Visit (initial encounter) initiates the work-up.
Evidence acquisition begins: Lab results and Imaging/Evidence provide the first clinical signals.
Biopsy may be performed to obtain histology.
Record the effective dates of each evidence item; these dates will later support condition assertion, staging, and treatment decisions.
Cancer Condition Assertion
Cancer Condition marks the start of the cancer journey and must include:
Histology Behaviour (cell type + behavior) — does not change over time.
Body Site (first detected location) — does not change over time.
Tumour Grade (biologic aggressiveness) — does not change over time.
Asserted Date — the first date the condition is documented (must tie to a report such as Visit, Biopsy, Surgery, Imaging, Biomarker, Lab Report).
Base of Diagnosis — procedure type underpinning assertion (e.g., Biopsy, Imaging, Lab).
Optional: Imaging Type / Biomarker Type used for detection.
Lifecycle rule:
A truly new, unrelated cancer → create a new Cancer Condition.
Extension/progression of the same cancer → update staging and Disease Status on the original condition.
The pair Histology Behaviour + Body Site identifies a Cancer Condition instance.
Staging & Disease Characterization
Clinical Stage (derived mainly from imaging and clinical evidence).
Pathological Stage (derived from surgery/histopathology).
Disease Extent can be represented by stage or other classification; it may evolve.
Disease Status (e.g., progression, partial/complete remission, recurrence) reflects the evolution of the Cancer Condition over time, typically evaluated at or around Visits using current evidence.
Temporality:
Stages can be updated as new evidence becomes available (e.g., after surgery for pathological stage).
Disease Status is time-stamped assessments that may recur along the timeline.
Treatment Planning & Treatment Episodes
Treatment represents procedures/therapies defined to treat the Cancer Condition and has an Intent: Definitive (curative) or Palliative.
Main treatment categories:
Surgery — characterized by a procedure date and target side.
Active Surveillance — start and end dates.
Radiotherapy — start, end, and target side.
Drug Administration — start and end (may be flagged ongoing, e.g., immunotherapy).
Treatments may be concurrent and are often grouped into a treatment episode. A single treatment can evolve (e.g., regimen changes), so maintain episode boundaries and versioning by dates.
Optionally, a Treatment Plan/Prescription may exist (especially for radiotherapy/drug therapy); while not in scope for v1, it can later document intended vs. actual care.
Monitoring & Follow-up
Ongoing Imaging/Evidence collection provides objective measures during and after therapy.
Visits anchor evaluations and decision points.
Adverse Events/Late Effects/Toxicities may occur and should be captured with occurrence dates and severity when available (often requires hospitalization data).
PROMs/QoL (if collected) give a patient-centered view of outcomes.
Treatment Response (per Treatment)
Treatment Response is the standard measure of how well a specific Treatment worked, determined by a clinician during a Visit and based on Evidence (imaging, labs, biomarkers). Typical values:
Date (visit date or evidence date; always tied to a documented report).
Do not conflate Treatment Response with Disease Status:
Treatment Response evaluates the effect of a given treatment.
Disease Status summarizes the overall condition trajectory over time.
Time & Instance Management (what changes vs. what stays fixed)
Fixed over time for a given Cancer Condition: Histology Behaviour, Body Site, Tumour Grade, Asserted Date (historical fact).
Evolves over time: Disease Status, Cancer Stage (clinical/pathological), Comorbidities, Treatments (episodes/regimens), Evidence (labs/imaging), Adverse Events, PROMs.
Create a new instance when: a new unrelated primary cancer is diagnosed (new Condition); a new treatment episode begins that is distinct in intent/regimen; a new response assessment is performed.
Update an existing instance when: staging is refined; status changes for the same condition; demographics/comorbidities change; a treatment continues with adjustments within the same episode.
