A 5 cm shadow on the lung is not necessarily early lung cancer. First of all, lung shadow is only a result of imaging examination, which can’t diagnose lung cancer, but may also be caused by inflammation, benign tumor and tuberculosis. Secondly, the staging of lung cancer should be based on the international TNM standard, if the tumor volume is only 5cm and there is no metastasis of lymph nodes and distal organs, the tumor is still in the early stage; once the patient is accompanied by metastasis of lymph nodes and distal organs, it is not an early stage of lung cancer, and it means that the patient has already entered into the middle stage or the late stage. In other words, a 5 cm shadow on the lung is not necessarily early stage lung cancer, but may also be benign tumor, or middle or late stage lung cancer.