Revisions to the Tumor, Node, Metastasis staging of lung cancer (8th edition): Rationale, radiologic findings and clinical implications

Table 1 Lung cancer staging, Tumor, Node, Metastasis staging 8^th edition

T	Primary tumor
	Tx	Cannot be assessed; Tumor in sputum/bronchial washings not in imaging/bronchoscopy
	To	No evidence
	Tis	Carcinoma in situ
	T1	≤ 3 cm surrounded by lung/visceral pleura, not involving main bronchus
	T1a(mi)	Minimally invasive adenocarcinoma
	T1a	≤ 1 cm
	T1b	> 1 to ≤ 2 cm
	T1c	> 2 to ≤ 3 cm
	T2	> 3 to ≤ 5 cm or Involves main bronchus without carina involvement or Visceral pleural invasion or atelectasis/post obstructive pneumonitis extending to hilum
	T2a	> 3 to ≤ 4 cm
	T2b	> 4 to ≤ 5 cm
	T3	> 5 to ≤ 7 cm or Separate tumor in same lobe or Direct invasion of chest wall (includes parietal pleura and superior sulcus)/parietal pericardium/phrenic nerve
	T4	> 7 cm or
		Separate tumor in different lobe of ipsilateral lung or Invasion of heart/ great vessels/diaphragm/mediastinum/trachea/carina/esophagus/ recurrent laryngeal nerve/vertebral body
N	Regional lymph node
	Nx	Cannot be assessed
	N0	No involvement
	N1	Ipsilateral peribronchial and/or hilar nodes and intrapulmonary nodes
	N2	Ipsilateral mediastinal and/or subcarinal nodes
	N3	Contralateral mediastinal or hilar; ipsilateral/contralateral scalene/supraclavicular
M	Distant metastasis
	M0	No distant metastasis
	M1	Distant metastasis is present
	M1a	Tumor (s) in contralateral lung; pleural/pericardial nodule/malignant effusion
	M1b	Single extrathoracic metastasis
	M1c	Multiple extrathoracic metastases, in one/more organs