Lung cancer (staging - IASLC 8th edition)

The IASLC (International Association for the Study of Lung Cancer) 8th edition lung cancer staging system was introduced in 2016 and supersedes the IASLC 7th edition

TNM system

T: primary tumour

  • Tx: primary tumour cannot be assessed or tumour proven by the presence of malignant cells in sputum or bronchial washings but not visualised by imaging or bronchoscopy
  • T0: no evidence of a primary tumour
  • Tis: carcinoma in situ
  • T1: tumour under 3 cm in greatest dimension surrounded by lung or visceral pleura without bronchoscopic evidence of invasion more proximal than the lobar bronchus (i.e. not in the main bronchus)
    • T1a(mi): minimally invasive adenocarcinoma
    • T1a ss: superficial spreading tumour in central airways (spreading tumour of any size but confined to the tracheal or bronchial wall)
    • T1a: tumour ≤1 cm in greatest dimension
    • T1b: tumour >1 cm but ≤2 cm in greatest dimension
    • T1c: tumour >2 cm but ≤3 cm in greatest dimension
  • T2: tumour >3 cm but ≤5 cm or tumour with any of the following features:
    • involves the main bronchus regardless of distance from the carina but without the involvement of the carina
    • invades visceral pleura
    • associated with atelectasis or obstructive pneumonitis that extends to the hilar region
    • involving part or all of the lung
    • T2a: tumour >3 cm but ≤4 cm in greatest dimension
    • T2b: tumour >4 cm but ≤5 cm in greatest dimension
  • T3: tumour >5 cm but ≤7 cm in greatest dimension or associated with separate tumour nodule(s) in the same lobe as the primary tumour or directly invades any of the following structures:
    • chest wall (including the parietal pleura and superior sulcus)
    • phrenic nerve
    • parietal pericardium
  • T4: tumour >7 cm in greatest dimension or associated with separate tumour nodule(s) in a different ipsilateral lobe than that of the primary tumour or invades any of the following structures
    • diaphragm
    • mediastinum
    • heart
    • great vessels
    • trachea
    • recurrent laryngeal nerve
    • oesophagus
    • vertebral body
    • carina

It is recommended that solid and non-solid lesions should be measured on the image that shows the greatest tumour dimension (on axial, coronal, or sagittal planes). Although those lesions that are part solid should be measured on both their largest average diameter and the largest diameter of the solid component, only the solid component measurement is to be used for staging directions 3. Also, the solid component of subsolid lesions should be performed on a lung or intermediate window rather than mediastinal window 3

N: regional lymph node involvement

  • Nx: regional lymph nodes cannot be assessed
  • N0: no regional lymph node metastasis
  • N1: metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extension
  • N2: metastasis in ipsilateral mediastinal and/or subcarinal lymph node(s)
  • N3: metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph node(s)

M: distant metastasis

  • M0: no distant metastasis
  • M1: distant metastasis present
    • M1a: separate tumour nodule(s) in a contralateral lobe; tumour with pleural or pericardial nodule(s) or malignant pleural or pericardial effusions
    • M1b: single extrathoracic metastasis
    • M1c: multiple extrathoracic metastases in one or more organs

There is a recommendation that the number of metastatic lesions, the larger diameter of individual metastatic deposits, and the number of involved organs should be stated in the radiological report 3

Stage groupings
  • stage 0
    • TNM equivalent: Tis, N0, M0
  • stage Ia
    • TNM equivalent: T1, N0, M0
    • 5-year survival: up to 92%
  • stage Ib
    • TNM equivalent: T2a, N0, M0
    • 5-year survival: 68%
  • stage IIa
    • TNM equivalent: T2b, N0, M0
    • 5-year survival: 60%
  • stage IIb
    • TNM equivalent: T1/T2, N1, M0 or T3, N0, M0
    • 5-year survival: 53%
  • stage IIIa
    • TNM equivalent: T1/T2, N2, M0 or T3/T4, N1, M0 or T4, N0, M0
    • 5-year survival: 36%
  • stage IIIb
    • TNM equivalent: T1/T2, N3, M0 or T3/T4, N2, M0
    • 5-year survival: 26%
  • stage IIIc
    • TNM equivalent: T3/T4, N3, M0
    • 5-year survival: 13%
  • stage IVa
    • TNM equivalent: any T, any N with M1a/M1b
    • 5-year survival: 10%
  • stage IVb
    • TNM equivalent: any T, any N with M1c
    • 5-year survival: 0%
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Article information

rID: 50570
System: Chest
Synonyms or Alternate Spellings:
  • NSCLC staging
  • IASLC 8th edition lung cancer staging
  • Non small cell lung cancer staging
  • Lung cancer staging
  • Lung cancer TNM

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