Primary tumor (T)

Tx

Tumor diagnosed based on tumor cells found in bronchial lavage but not radiographically or bronchoscopically visualized

T0

No evidence of primary tumor

Tis

Pre-invasive carcinoma (in situ)

T1

Tumor ≤3 cm in greatest dimension, surrounded by pulmonary or visceral pleura, without bronchoscopic evidence of invasion in the main bronchusa

T1(mi)

Minimally invasive adenocarcinomab

T1a

Tumor ≤1 cma in greatest dimension

T1b

Tumor >1 cm but ≤2 cma in greatest dimension

T1c

Tumor >2 cm but ≤3 cma in greatest dimension

T2

Tumor >3 cm but ≤5 cm in greatest dimension or with ≥1 of the following:

– Involving the main bronchus, but not reaching bifurcation of the trachea

– Involving the visceral pleura

– Causing atelectasis or pneumonitis extending to the hilum area, partial or complete

T2a

Tumor >3 cm but ≤4 cm in greatest dimension

T2b

Tumor >4 cm but ≤5 cm in greatest dimension

T3

Tumor >5 cm but ≤7 cm in greatest dimension or with ≥1 of the following:

– Directly infiltrating the parietal pleura, chest wall (including tumor of the apex of the lung), phrenic nerve, or pericardium

– Tumor with separate tumor foci within the same lobe

T4

Tumor >7 cm in greatest dimension or ≥1 of the following:

– Invading the diaphragm, mediastinum, heart, large vessels, trachea, retrograde laryngeal nerve, esophagus, tracheal bifurcation, or vertebral body

– Tumor with separate tumor foci within a different lobe of the same lung

Regional lymph nodes (N)

Nx

Regional lymph nodes cannot be assessed

N0

No metastases in regional lymph nodes

N1

Metastases in ipsilateral peribronchial or hilar nodes or their direct invasion

N2

Metastases in ipsilateral mediastinal and/or subcarinal nodes

N3

Metastases in contralateral hilar or mediastinal nodes, metastases in supraclavicular nodes

Distant metastases (M)

Mx

Distant metastases cannot be assessed

M0

No distant metastases

M1a

– Separate tumor nodule(s) in contralateral lung

– Malignant foci in the pleura or pericardium, or malignant pleural or pericardial effusionc

M1b

Single distant (extrathoracic) metastasesd

M1c

Multiple distant (extrathoracic) metastases in ≥1 organ

a Rare, superficial tumors of any size with invasion confined to the bronchial wall (including the main bronchus) are also classified as T1a.

b A solitary adenocarcinoma ≤3 cm, lepidic predominant tumor of the interalveolar septa, with ≤5-mm invasion in one of the foci.

c Pleural or pericardial fluid in patients with lung cancer is usually malignant. In a minority of patients, microscopic examination of the pleural or pericardial fluid does not reveal malignant cells, the fluid does not contain blood and is not exudative. If there are no clinical indications to link the exudate to tumor, the presence of pleural or pericardial fluid does not affect the tumor staging.

d Also applies to a single distant (nonregional) lymph node.