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Non-Small Cell Lung Cancer Treatment (PDQ®)

  • Updated: 02/21/2014

Table 10. Definitions of TNM Stage IVa

Stage TNM Description Illustration 
IVAny T, Any N, M1a OR Any T, Any N, M1bTX = 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.
T0 = No evidence of primary tumor.
Tis = Carcinoma in situ.
T2 = Tumor >3 cm but ≤7 cm in greatest dimension, or tumor with any of the following features (T2 tumors with these features are classified T2a if ≤5 cm): involves main bronchus, ≥2 cm distal to the carina; invades visceral pleura (PL1 or PL2); or is associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung.
T3 = Tumor >7 cm or one that directly invades any of the following: parietal pleural (PL3) chest wall (including superior sulcus tumors), diaphragm, phrenic nerve, mediastinal pleura, or parietal pericardium or tumor in the main bronchus (<2 cm distal to the carinab 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 = Tumor of any size that invades any of the following: mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina, or separate tumor nodule(s) in a different ipsilateral lobe.
NX = Regional lymph nodes cannot be assessed.
N0 = No regional lymph node metastasis.
N1 = Metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extension.
N2 = Metastasis in ipsilateral mediastinal and/or subcarinal lymph node(s).
M0 = No distant metastasis.
M1 = Distant metastasis.
M1a = Separate tumor nodule(s) in a contralateral lobe tumor with pleural nodules or malignant pleural (or pericardial) effusion.c
M1b = Distant metastasis (in extrathoracic organs).

bThe uncommon superficial spreading of the tumor of any size with its invasive component limited to the bronchial wall, which may extend proximally to the main bronchus, is also classified as T1a.
cMost pleural (and pericardial) effusions with lung cancer are due to tumor. In a few patients, however, multiple cytopathologic examinations of pleural (pericardial) fluid are negative for tumor, and the fluid is nonbloody and is not an exudate. Where these elements and clinical judgment dictate that the effusion is not related to the tumor, the effusion should be excluded as a staging element, and the patient should be classified as M0.