International Staging System for Lung Cancer

Primary tumor (T)

Tis

Carcinoma in situ

T1

Tumor ≤ 3 cm without invasion more proximal than the lobar bronchus

T1mi

Minimally invasive adenocarcinoma

T1a

Tumor ≤ 1 cm

or

Tumor of any size whose invasive component is limited to the bronchial wall and may extend proximal to the main bronchus

T1b

Tumor > 1 cm but ≤ 2 cm

T1c

Tumor > 2 cm but ≤ 3 cm

T2

Tumor > 3 cm but ≤ 5 cm or with any of the following:

or

Tumor ≤ 4 cm with one or more of the following features:

• Invades the visceral pleura

• Invades an adjacent lobe

• Involves the main bronchus (up to but not including the carina)

  or

• Associated with atelectasis or obstructive pneumonitis, extending to the hilar regions, involving either part of or the entire lung

T2a

Tumor > 3 but ≤ 4 cm

or

Tumor ≤ 4 cm in greatest dimension with one or more of the following features:

• Invades the visceral pleura

• Invades an adjacent lobe

• Involves the main bronchus (up to but not including the carina)

  or

• Associated with atelectasis or obstructive pneumonitis, extending to the hilar regions, involving either part of or the entire lung

T2b

Tumor > 4 but ≤ 5 cm in greatest dimension with or without any of the following features:

• Invades the visceral pleura

• Invades an adjacent lobe

• Involves the main bronchus (up to but not including the carina)

  or

• Associated with atelectasis or obstructive pneumonitis, extending to the hilar regions, involving either part of or the entire lung

T3

Tumor > 5 cm but ≤ 7 cm

or

Tumor ≤ 7 cm with one or more of the following features:

• Invades the parietal pleura or chest wall

• Invades the pericardium, phrenic nerve or azygos vein

• Invades thoracic nerve roots or stellate ganglion

• Separate tumor nodule(s) in the same lobe as the primary

T4

Tumor > 7 cm or with either of the following:

• Invades the diaphragm, mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, or carina

• ≥ 1 Satellite tumors in a different ipsilateral lobe

Regional lymph nodes (N)

N0

No regional lymph node metastasis

N1

Metastasis to ipsilateral peribronchial or ipsilateral hilar lymph node or both and to intrapulmonary nodes, including that by direct extension of the primary tumor

N2

Metastasis to ipsilateral mediastinal or subcarinal lymph node or both

N2a

Involvement of a single N2 lymph node station

N2b

Involvement of multiple N2 stations

N3

Metastasis to contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph node, or a combination

Distant metastasis (M)

M0

No distant metastasis

M1

Distant metastasis

M1a

Tumor with any of the following:

• ≥ 1 Tumor nodules in the contralateral lung

• Pleural or pericardial nodules

• Malignant pleural or pericardial effusion

M1b

Single extrathoracic metastasis in a single organ

M1c

Multiple extrathoracic metastases in one or several organs

M1c1

Multiple extrathoracic metastases in a single organ system

M1c2

Multiple extrathoracic metastases in multiple organ systems

Stage groupings

• Stage 0: Tis N0 M0

• Stage IA1: T1mi–T1a N0 M0

• Stage IA2: T1b N0 M0

• Stage IA3: T1c N0 M0

• Stage IB: T2a N0 M0

• Stage IIA: T2b N0 M0 or T1 N1 M0

• Stage IIB: T1-T2b N2a-N0a M0 or T3 N0 M0

• Stage IIIA: T1 N2b M0 or T2-T3 N2a M0 or T3-T4 N1-N0 M0

• Stage IIIB: T1-T2 N3 M0 or T2-T3 N2b M0 or T4 N2a-N2b M0

• Stage IIIC: T3-T4 N3 M0

• Stage IVA: T (any) N (any) M1a–M1b

• Stage IVB: T (any) N (any) M1c