# Radiation Oncology/NSCLC/Staging

* Front Page: Radiation Oncology | RTOG Trials | Randomized Trials
Lung Cancer Staging
AJCC 8th edition (2017)
Source:
Primary Tumor:
* TX - primary tumor cannot be assessed, or tumor proven by malignant cells in sputum or bronchial washings but not visualized by imaging or bronchoscopy
* Tis - Carcinoma in situ:
** Tis (AIS): adenocarcinoma
** Tis (SCIS): squamous cell carcinoma
* T1 - 3 cm or less, surrounded by lung or visceral pleura, not invading into a main bronchus
** (the uncommon superficial spreading tumor of any size with its invasive component limited to the bronchial wall, which may extend proximal to the main bronchus, is also classified as T1a)
** T1mi - minimally invasive adenocarcinoma
** T1a - tumor 1 cm or less
** T1b - >1 cm but ≤ 2 cm
** T1c - >2 cm but ≤ 3 cm
* T2 - tumor >3 cm but ≤ 5 cm; or tumor with any of the following
** involves main bronchus (regardless of distance to the carina, but without invading the carina)
** invades visceral pleura (PL1 or PL2)
** associated with atelectasis or obstructive pneumonitis that extends to the hilar region, either involving part of the lung or the entire lung
    (T2 tumors with these features are classified T2a if 4 cm or less and as T2b if >4 cm but ≤ 5 cm)
** T2a - >3 cm but ≤ 4 cm (also includes T2 tumors smaller than 4 cm)
** T2b - >4 cm but ≤ 5 cm
* T3 - tumor >5 cm but ≤ 7 cm; or tumor that directly invades one of the following: parietal pleura (PL3), chest wall, phrenic nerve, parietal pericardium; or separate tumor nodules in the same lobe
* T4 - > 7 cm, or tumor invades: diaphragm, mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina; or separate tumor nodule(s) in a different ipsilateral lobe
Regional Lymph Nodes:
* N0 - no nodes
* N1 - ipsilateral peribronchial and/or ipsilateral hilar lymph nodes or intrapulmonary nodes
* N2 - ipsilateral mediastinal and/or subcarinal nodes
* N3 - contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene or supraclavicular nodes
Distant Metastases:
* M0 - none
* M1
** M1a - separate tumor nodule(s) in a contralateral lobe; tumor with pleural nodules or malignant pleural or pericardial effusion
** M1b - single extrathoracic metastasis in a single organ and involvement of a single distant (nonregional) node
** M1c - multiple extrathoracic metastases in one or several organs
Stage Grouping:
* IA1 - T1mi or T1a, N0
* IA2 - T1b N0
* IA3 - T1c N0
* IB - T2a N0
* IIA - T2b N0
* IIB - T1 N1; T2 N1; T3 N0
* IIIA - T1-2 N2; T3 N1; T4 N0-1
* IIIB - T1-2 N3; T3-4 N2
* IIIC - T3-4 N3
* IVA - M1a or M1b
* IVB - M1c
Classification of situations not covered by TNM descriptors:
* paralysis of recurrent laryngeal nerve, SVC obstructions, and compression of trachea or esophagus related to direct extension of the primary tumor are classified as T4 but would be classified as N2 if caused by ipsilateral mediastinal nodal disease
* Pancoast (superior sulcus) tumors are classified as T4 if there is evidence of invasion of the vertebral body or spinal canal, encasement of the subclavian vessels, or unequivocal involvement of the superior branches of the brachial plexus (C8 or above) but as T3 if these situations are not present
* direct invasion of an adjacent lobe, across the fissure or indirectly if the fissure is incomplete, is classified as T2a
* invasion of the phrenic nerve is T3, but invasion of the recurrent laryngeal nerve is T4
* invasion into hilar fat is classified as T2a
* direct extension to visceral pericardium and invasion into the mediastinal fat are T4
* involvement of the great vessels, ie, aorta, SVC, IVC, main pulmonary artery (pulmonary trunk), intrapericardial portions of the superior and inferior right and left pulmonary veins, is T4
* discontinuous tumor nodules in the ipsilateral parietal or visceral pleura are classified as M1a; but, if the tumor nodules are outside the parietal pleura in the chest wall or in the diaphragm, they are classified as M1b, if single, or M1c, if multiple

## Older staging editions

AJCC 7th Edition (2009)
* corresponds with IASLC staging - published: PMID 19584208 (Chest 2009 Jul;136(1):260-71.)
* IASLC document (PDF)
Primary Tumor:
* T1 - 3 cm or less, surrounded by lung or visceral pleura, not invading into a main bronchus
** T1a - tumor 2 cm or less
** T1b - > 2 cm but <= 3 cm
* T2 - tumor >3 cm but <= 7 cm; or tumor with any of the following: involves main bronchus (2cm or more distal to the carina), invades visceral pleura (PL1 or PL2); associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung
** T2a - >3 cm but <= 5 cm (also includes T2 tumors smaller than 3 cm)
** T2b - >5 cm but <= 7 cm
* T3 - tumor > 7 cm; or tumor that directly invades one of the following: parietal pleura (PL3), chest wall, diaphragm, phrenic nerve, mediastinal pleura, parietal pericardium; or tumor in the main bronchus less than 2 cm distal to the carina; or associated atelectasis or obstructive pneumonitis of the entire lung; or separate tumor nodules in the same lobe
* T4 - tumor invades: mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina; or separate tumor nodule(s) in a different ipsilateral lobe
* Note: Great vessels include aorta, superior vena cava, inferior vena cava, main pulmonary A, intrapericardial segments of the trunk of the R and L pulmonary A, intrapericardial segments of the R and L pulmonary V.
Regional Lymph Nodes:
* N0 - no nodes
* N1 - ipsilateral peribronchial and/or ipsilateral hilar lymph nodes or intrapulmonary nodes
* N2 - ipsilateral mediastinal and/or subcarinal nodes
* N3 - contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene or supraclavicular nodes
Distant Metastases:
* M0 - none
* M1
** M1a - separate tumor nodule(s) in a contralateral lobe; tumor with pleural nodules or malignant pleural or pericardial effusion
** M1b - distant metastases
Stage Grouping:
* IA - T1(a or b) N0
* IB - T2a N0
* IIA - T1(a or b) N1, T2a N1, T2b N0
* IIB - T2b N1, T3 N0
* IIIA - T3 N1, T1-3 N2, T4 N0-1
* IIIB - N3 any, T4 N2-3
* IV - M1a or M1b
Pleural Invasion:
* Uses modification of Hammar classification -- see PMID 19057261 (Travis WD, "Visceral pleural invasion: pathologic criteria and use of elastic stains: proposal for the 7th edition of the TNM classification for lung cancer." J Thorac Oncol. 2008 Dec;3(12):1384-90.)
* PL0 - Tumor within the subpleural parenchyma or, invading superficially into the pleural connective tissue below the elastic layer.
* PL1 - Tumor invades beyond the elastic layer.
* PL2 - Tumor invades to visceral pleural surface.
* PL3 - Tumor invades the parietal pleura.
Note:
* The 7th Edition recommended that AJCC staging be applied to Small Cell Lung Cancer and Pulmonary Carcinoid Tumors
AJCC 6th Edition (2002)
Primary Tumor:
* T1 - 3 cm or less, surrounded by lung or visceral pleura, not invading into a main bronchus
* T2 - Any of the following: 1) more than 3 cm, 2) involves main bronchus, 2 cm or more distal to the carina, 3) invades the visceral pleura, 4) associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung
* T3 - Tumor of any size that invades any of the following: 1) chest wall, 2) diaphragm, 3) mediastinal pleura, 4) parietal pericardium; or 5) tumor in the main bronchus less than 2 cm distal to the carina but without involvement of the carina; or 6) associated atelectasis or obstructive pneumonitis of the entire lung
* T4 - Tumor of any size that invades any of the following:
** 1) mediastinum, 2) heart, 3) great vessels, 4) trachea, 5) esophagus, 6) vertebral body, or 7) carina;
** 8) separate tumor nodules in the same lobe;
** 9) malignant pleural effusion
Regional Lymph Nodes:
* N0 - no nodes
* N1 - ipsilateral peribronchial and/or ipsilateral hilar lymph nodes or intrapulmonary nodes
* N2 - ipsilateral mediastinal and/or subcarinal nodes
* N3 - contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene or supraclavicular nodes
Distant Metastases:
* M0 - no
* M1 - yes
** includes separate tumor nodules in a different lobe (ipsilateral or contralateral)
Stage Grouping:
* IA - T1 N0
* IB - T2 N0
* IIA - T1 N1
* IIB - T2 N1, T3 N0
* IIIA - T3 N1, T1-3 N2
* IIIB - N3 or T4
** T4 N0-1 (invasive but potentially resectable; includes upstaged to T4 due to satellite lesions)
** T4 N0-1 (upstaged to T4 because of pleural/pericardial effusion; unresectable)
** T4 N2-3 (invasive and mediastinal+ LNs; unresectable)
** T1-3 N3 (possibly smaller but contralateral LNs; unresectable)
* IV - M1
NOTE: the 1997 AJCC Staging System moved T3,N0 from Stage III to IIB, complicating the interpretation of older trials of Stage III patients which would have had better prognosis.