The staging of squamous lung cancer can refer to the 8th edition of TNM staging system for lung cancer published by the International Society for the Study of Lung Cancer (ISSLC).T stands for primary tumor, N stands for regional lymph nodes and M stands for distant metastasis. 1. primary tumor (T): Tx means no primary tumor is found. tis is carcinoma in situ. t1~t3 is staged by the largest diameter of the tumor. t1~t3 is staged by the largest diameter of the tumor. t1~t3 is staged by the largest diameter of the tumor. Or direct invasion of any of the organs in the chest wall, phrenic nerve, or pericardium. T4 represents the tumor with a maximum diameter of >7cm, or invading any of the organs in the mediastinum, heart, great vessels, recurrent laryngeal nerve, main trachea, esophagus, diaphragm, and vertebrae. 2. Regional lymph nodes (N): Nx means that regional lymph nodes cannot be evaluated; N0 means that there is no regional lymph node metastasis; N1 means that ipsilateral lymph nodes or lymph nodes in the lungs have metastasized; N2 means that the ipsilateral mediastinal lymph nodes have metastasized. N2 represents metastasis in the ipsilateral mediastinum or infratentorial lymph nodes. n3 represents metastasis in the contralateral mediastinum, hilar, ipsilateral or contralateral anterior oblique muscle, and supraclavicular lymph nodes. 3. Distant metastasis (M): Mx means that the presence of distant metastasis cannot be assessed; M0 means that no distant metastasis has occurred; M1 means that distant metastasis is present.