Table 2.

Classification of malignant tumours, 2017 [23].

T	Size (cm)	Solitary vs. Multiple Nodules	Organ Invasion
T1	≤3	Solitary	None
T2	>3 to ≤5	Solitary	Visceral pleura, main bronchi (not carina)
T3	>5 to ≤7	Separate nodule(s) in same lobe	Chest wall, pericardium, phrenic nerve
T4	>7	Separate nodule(s) in ipsilateral lung lobe(s)	Mediastinum, diaphragm, heart, great vessels, recurrent laryngeal, nerve, carina, trachea, oesophagus, spine
N
N0	No lymph node metastasis
N1	Ipsilateral tracheobronchial lymph node
N2	Distant lymph node metastasis
M
M0	No distant metastasis
M1	Malignant effusion, contralateral lung lobe metastasis, extra-thoracic metastasis
Stage 1	T1, N0, M0
Stage 2	T2, N0, M0; T3, N0, M0; T1–2, N1, M0
Stage 3	T4, N0, M0; T3–4, N1, M0; T1–4, N2, M0
Stage 4	T1–4, N1–2, M1