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Andrey Bychkov, M.D., Ph.D.

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PubMed Search: Staging lung tumor

Andrey Bychkov, M.D., Ph.D.
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Cite this page: Bychkov A. Staging. website. Accessed April 14th, 2024.
Pathologic TNM staging of carcinomas of the lung, AJCC 8th edition
Definition / general
  • Applicable to carcinomas of the lung, including non small cell and small cell carcinomas and bronchopulmonary carcinoid tumors, does not apply to sarcomas or other rare tumors of the lung
  • WHO has defined new entities of adenocarcinoma in situ and minimally invasive adenocarcinoma, which are assigned to Tis and T1mi categories, respectively
Essential features
  • T, N and M categories code the anatomic extent of lung cancer and predict overall survival of patients with non small cell and small cell carcinomas
  • The 8th edition AJCC / TNM classification has provided a more comprehensive stratification of tumors based on subdivision of T, N and M categories and also adopted the newly introduced histological entities of lung carcinoma
ICD coding
  • C34.0: Main bronchus
  • C34.1: Upper lobe, lung
  • C34.2: Middle lobe, lung
  • C34.3: Lower lobe, lung
  • C34.8: Overlapping lesion of lung
  • C34.9: Lung, not otherwise specified (NOS)
Diagrams / tables

Images hosted on other servers:
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Staging chart

Primary tumor (pT)
  • pTX: primary tumor cannot be assessed or tumor proven by the presence of malignant cells in sputum or bronchial washings but not visualized by imaging or bronchoscopy
  • pT0: no evidence of primary tumor
  • pTis: carcinoma in situ, squamous cell carcinoma in situ, adenocarcinoma in situ (pure lepidic pattern and ≤ 3 cm)
  • pT1mi: minimally invasive adenocarcinoma (≤ 3 cm with a predominantly lepidic pattern and ≤ 5 mm of invasion)
  • pT1a: tumor ≤ 1 cm or rarely a superficial, spreading tumor of any size with invasive component limited to the bronchial wall that may extend proximal to the main bronchus
  • pT1b: tumor > 1 cm but ≤ 2 cm
  • pT1c: tumor > 2 cm but ≤ 3 cm
  • pT2: tumor > 3 cm but ≤ 5 cm or involves the main bronchus regardless of distance to the carina without involvement of the carina, invades visceral pleura (PL1 or PL2) or is associated with atelectasis or obstructive pneumonitis that extends to the hilar region involving part or all of the lung
    • pT2a: tumor > 3 cm but ≤ 4 cm or has 1 of the above features and size cannot be determined
    • pT2b: tumor > 4 cm but ≤ 5 cm
  • pT3: tumor > 5 cm but ≤ 7 cm or directly invades parietal pleura (PL3), chest wall (including superior sulcus tumors), phrenic nerve or parietal pericardium or presence of a separate tumor nodule in the same lobe
  • pT4: tumor > 7 cm or tumor of any size invading diaphragm, mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body or carina or presence of a separate tumor nodule in an ipsilateral different lobe

  • Tumor size has important prognostic relevance; each centimeter increase in size, from less than 1 cm to up to 5 cm, yields a significantly different prognosis
  • Multiple separate nodules are classified into four disease patterns (J Thorac Oncol 2016;11:639):
    • Multiple primary tumors
    • Nodules of the same histopathological type
    • Multiple tumors with predominant ground glass features on CT and a lepidic pattern on pathological examination
    • Diffuse pneumonic type lung cancer
  • Multiple primary tumors
    • Considered separate primary tumors if different histologic types (e.g., squamous carcinoma and adenocarcinoma) or are squamous carcinomas that have arisen from carcinoma in situ
    • Different biomarker pattern and absence of nodal or systemic metastases favor multiple primary tumors
  • Single primary tumor
    • Considered to have arisen from a single tumor if an exact match by comparative genomic hybridization
    • Similar histologic appearance, matching biomarker patterns and significant nodal or systemic metastases favor a single primary tumor
Regional lymph node (pN)
  • pNX: regional lymph nodes cannot be assessed
  • pN0: no regional lymph nodes metastasis
  • pN1: metastasis in ipsilateral peribronchial, ipsilateral hilar or intrapulmonary lymph node, including involvement by direct extension
  • pN2: metastasis in ipsilateral mediastinal or subcarinal lymph node
  • pN3: metastasis in contralateral mediastinal, contralateral hilar, ipsilateral / contralateral scalene or supraclavicular lymph node

  • In addition to anatomic extent of nodal disease, quantification based on the number of involved lymph node stations has prognostic impact
Distant metastasis (pM)
  • pM0: no distant metastasis
  • pM1a: separate tumor nodule in a contralateral lobe, pleural nodules, pericardial nodules, malignant pleural effusion or malignant pericardial effusion
  • pM1b: single extrathoracic metastasis in a single organ (including a single non regional node)
  • pM1c: multiple extrathoracic metastases in a single organ or in multiple organs

  • Most pleural and pericardial effusions are a result of the tumor
  • Rarely, fluids are negative for tumor, non bloody and not an exudate; clinical judgment is required in these cases
    • Number of distant metastases has more prognostic relevance than organ location
AJCC prognostic stage grouping
Occult carcinoma: TX N0 M0
Stage 0: Tis N0 M0
Stage IA1: T1mi N0 M0
T1a N0 M0
Stage IA2: T1b N0 M0
Stage IA3: T1c N0 M0
Stage IB: T2a N0 M0
Stage IIA: T2b N0 M0
Stage IIB: T1a - c N1 M0
T2a - b N1 M0
T3 N0 M0
Stage IIIA: T1a - c N2 M0
T2a - b N2 M0
T3 N1 M0
T4 N0 - 1 M0
Stage IIIB: T1a - c N3 M0
T2a - b N3 M0
T3 - 4 N2 M0
Stage IIIC: T3 - 4 N3 M0
Survival data
Overall survival
2 years 5 years
Clinical stage  Pathological stage  Clinical stage  Pathological stage 
Stage IA1   97% 97% 92% 90%
Stage IA2 94% 94% 83% 85%
Stage IA3 90% 92% 77% 80%
Stage IB 87% 68% 89% 73%
Stage IIA 79% 82% 60% 65%
Stage IIB 72% 76% 53% 56%
Stage IIIA 55% 65% 36% 41%
Stage IIIB 44% 47% 28% 24%
Stage IIIC 24% 30% 13% 12%
Stage IVA 23% NA 10% NA
Stage IVB 10% NA 0% NA
Registry data collection variables
  • For surgically resected non small cell lung cancer
    • Gender
    • Age
    • Weight loss
    • Performance status
    • Resection margins
    • Adequacy of mediastinal dissection
  • For advanced non small cell lung cancer
    • EGFR mutation
    • ALK gene rearrangement
    • Gender
    • Symptoms
    • Weight loss
    • Performance status
    • Chemoradiotherapy
    • Chemotherapy
  • For small cell lung cancer
    • Performance status
    • Age
    • Comorbidity
    • Chemotherapy
    • Thoracic radiotherapy
    • Prophylactic cranial radiotherapy
  • Pathological variables for surgically resected non small cell lung cancer (Gospodarowicz: Prognostic Factors in Cancer, 3rd Edition, 2006):
    • Histologic type
    • Differentiation grade
    • Vascular invasion
    • Lymphatic permeation
    • Perineural invasion
    • Type of visceral pleura invasion: PL1 versus PL2
    • Positive pleural lavage cytology
    • SUVmax of primary tumor
    • Molecular / biologic markers
Histologic grade
  • GX: grade of differentiation cannot be assessed
  • G1: well differentiated
  • G2: moderately differentiated
  • G3: poorly differentiated
  • G4: undifferentiated

Staging animation

Updates on TNM staging (2017)

8th TNM classification (2018)

Additional references
Board review style question #1
    A CT detected a ground glass nodule in the upper lung. Surgical resection revealed a 2 cm adenocarcinoma with pure lepidic pattern and no stromal invasion. What is the pT category?

  1. pT0
  2. pT1a
  3. pT1b
  4. pT1mi
  5. pTis
Board review style answer #1
E. pTis. The pTis category for adenocarcinoma in situ was added in the AJCC / TNM 8th edition staging scheme. By definition, this is a localized, small (≤ 3 cm) adenocarcinoma with growth restricted to neoplastic cells along pre-existing alveolar structures (lepidic growth) and lacking stromal, vascular, alveolar space or pleural invasion. Radiologic equivalent is a pure ground glass nodule on CT. In contrast, minimally invasive adenocarcinoma (pT1mi) is defined as a lepidic predominant adenocarcinoma measuring up to 3 cm with an invasive component measuring up to 0.5 cm.

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Reference: Lung - Staging
Board review style question #2
    What is the correct pM category for a lung carcinoma with an ipsilateral malignant pleural effusion?

  1. pM0
  2. pM1a
  3. pM1b
  4. pM1c
Board review style answer #2
B. pM1a. A lung carcinoma with pleural or pericardial nodules or with a proven malignant pleural or pericardial effusion is defined as pM1a.

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Reference: Lung - Staging
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