Lung Cancer Staging

The American Joint Committee on Cancer (AJCC) uses the TNM classification to define the stages of Lung cancer:

T is for Tumor. The number after the T indicates the size of the tumor and how far it has invaded. The larger the number, the bigger and/or more invasive the cancer.

• TX means the primary tumor cannot be assessed.
• T0 means there is no evidence of primary tumor.
• T1 means the tumor is 3cm or less in greatest dimension, surrounded by lung or visceral pleura, not in the main bronchus.

·       T1a means the tumor is 2 cm or less in greatest dimension.

·       T1b means the tumor is more than 2 cm but 3cm or less in greatest dimension.

• T2 means the tumor is more than 3cm but 7cm or less or tumor has any of the following features: Involves main bronchus, 2cm or more distal to the carina; Invades visceral pleura; Associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung.
  • T2a means the tumor is more than 3cm but 5cm or less in greatest dimension.
  • T2b means the tumor is more than 5cm but 7cm or less in greatest dimension.
• T3 means the tumor is more than 7cm or one that directly invades any of the following: parietal pleural chest wall, diaphragm, phrenic nerve, mediastinal pleura, parietal pericardium; or tumor in the main bronchus but without involvement of the carina; or associated atelectasis or obstructive pneumonitis of the entire lung or separate tumor nodule(s) in the same lobe.
• T4 means tumor of any size that invades any of the following: mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina, separate tumor nodule(s) in a different ipsilateral lobe.

N is for Nodes. The number after the N indicates whether the cancer has spread to the lymph nodes and to what extent.

• NX means the regional lymph nodes cannot be assessed.
• N0 means there is no cancer in the lymph nodes in the region of the cancer.
• N1 means there has been metastasis in ipsilateral (same side) peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extension.
• N2 means there has been metastasis in ipsilateral (same side) mediastinal and/or subcarinal lymph node(s).
• N3 means there has been metastasis in contralateral (opposite side) mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph node(s).

M is for Metastasis. The number after the M indicates whether the cancer has spread to distant areas of the body.

• M0 means there is no distant metastasis.
• M1 means there is distant metastasis.
• M1a means there are separate tumor nodule(s) in a contralateral (opposite side) lobe tumor with pleural nodules or malignant pleural (or pericardial) effusion.
• M1b Distant metastasis.

Stage Grouping