TUMOR (T) STATUS

• T0 No evidence of a primary tumor

• TX 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

• TIS Carcinoma in situ

• T1 Tumor <3 cm in greatest dimension, surrounded by lung or visceral pleura, without bronchoscopic evidence of invasion more proximal than lobar bronchus (i.e., not in main bronchus)

• T2 Tumor with any of following: >3 cm in greatest dimension; involves main bronchus, >2 cm distal to the carina; invades visceral pleura; associated with atelectasis or obstructive pneumonitis extending to hilum but does not involve entire lung

• T3 Tumor of any size that directly invades any of the following: chest wall (including superior sulcus tumors), diaphragm, mediastinal pleura, parietal pericardium; or tumor in main bronchus <2 cm distal to carina but without involvement of carina; or associated atelectasis or obstructive pneumonitis of entire lung

• T4 Tumor of any size that invades any of the following: mediastinum, heart, great vessels, trachea, esophagus, vertebral body, carina; or tumor with a malignant pleural or pericardial effusion^a, or with satellite tumor nodule(s) within the ipsilateral primary-tumor lobe of the lung.

LYMPH NODE (N) INVOLVEMENT

• NX Regional lymph nodes cannot be assessed

• N0 No regional lymph node metastasis

• N1 Metastasis to ipsilateral peribronchial and/or ipsilateral hilar lymph nodes, and intrapulmonary nodes involved by direct extension of the primary tumor

• N2 Metastasis to ipsilateral mediastinal and/or subcarinal lymph nodes(s)

• N3 Metastasis to contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph node(s)

DISTANT METASTASIS (M)

• MX Presence of distant metastasis cannot be assessed

• M0 No distant metastasis

• M1 Distant metastasis present^b

^a Most pleural effusions associated with lung cancer are due to tumor. However, in a few patients with multiple negative cytopathologic exams of a non-bloody, non-exudative pleural or pericardial effusion that clinical judgment dictates is not related to the tumor, the effusion should be excluded as a staging element and the patient’s disease staged as T1, T2, or T3.

^b Separate metastatic pulmonary tumor nodule(s) in the ipsilateral nonprimary tumor lobe(s) of the lung are classified as M1.

References:

1. Mountain CF. Revisions in the International System for Staging Lung Cancer. Chest. 1997 Jun;111(6):1710-7. [Medline]