ONCOLOGY · NON-SMALL CELL LUNG CARCINOMA
Lung cancer TNM staging: AJCC Version 9 examples
Learn how primary tumour extent, regional nodal stations and distant spread combine in NSCLC staging, then practise with the TNMAtlas calculator.
Open the lung staging calculator ↗Start with the correct staging system
This guide uses AJCC Version 9 for lung, introduced in 2025 and listed in AJCC’s 2026 current systems document. AJCC updates are disease-specific; this label does not mean that every organ uses the same edition. [1]
Use this guide for learning initial NSCLC staging. The calculator does not provide post-neoadjuvant or recurrent stage groups, treatment recommendations or independent clinical validation.
Build T, N and M separately
Primary extent
Consider size and invasion. A higher local-extension feature can override a size-only category.
Regional stations
N2a involves one ipsilateral mediastinal/subcarinal station; N2b involves multiple such stations. Count stations, not individual nodes.
Distant distribution
M1c1 means multiple extrathoracic metastases in one organ system; M1c2 involves multiple organ systems. [2]
One changed finding, a different group
Hold the primary tumour and distant assessment constant. Compare one involved mediastinal station with two.
One involved station
T1c N2a M0 → IIB
Two involved stations
T1c N2b M0 → IIIA
The drawings highlight the changed nodal distribution. Station boundaries are symbolic; they are not a procedural lymph-node map.
Three worked examples
Example 1 · Initial clinical
One station
A 2.5 cm primary with no higher T feature, one involved ipsilateral mediastinal station and no distant metastasis.
cT1c cN2a cM0
Stage IIBExample 2 · Initial clinical
Two stations
Keep all other findings unchanged; establish involvement of a second ipsilateral mediastinal station.
cT1c cN2b cM0
Stage IIIAExample 3 · Initial clinical
Distant bone lesions
A 4.4 cm primary, ipsilateral hilar involvement and several bone metastases, without another distant organ system.
cT2b cN1 cM1c1
Stage IVBFictional examples; category definitions and groups checked against NCI PDQ, Tables 1–4. [2]
How to use the calculator
- Open TNMAtlas and keep Lung selected.
- Choose the appropriate classification and initial assessment context.
- Enter the established T, N and M categories. Leave uncertain findings unresolved rather than assuming they are negative.
- Compare the result and explanation with the cited source. Record the edition and evidence behind the categories.
Use the atlas’s fictional examples to practise. Do not enter identifiable patient information into learning notes.
Practise in TNMAtlas ↗References
- AJCC: Current staging systems for 2026 — disease-specific edition applicability.
- NCI PDQ: Non-small cell lung cancer treatment — stage information, Tables 1–4. Full descriptors and exceptions remain in the reference.