The time needed for lung cancer to develop into middle or late stage ranges from a few months to a few years, the time span is relatively large, or some patients will not develop into middle or late stage. The time needed for lung cancer to develop into middle or late stage is affected by various clinical factors, including the clinical stage of lung cancer, the malignancy of the pathological type of lung cancer, the anti-tumor treatment received by the patient, and the effectiveness of the treatment, etc. Generally speaking, the later the stage, the more malignant the lung cancer is, and the more effective the treatment is, the more patients will not be treated. Generally, the later the stage, the more malignant the disease is, and no treatment or ineffective treatment will shorten the time to develop to the middle and late stages. For small cell lung cancer with high malignancy, if no treatment is given or chemotherapy and other anti-tumor treatments are ineffective for the patient, it may only take a few months for patients with limited stage to develop to middle or late stage. And generally early lung cancer, given timely surgical treatment, the percentage of patients cured is relatively high, and the lesions may not develop to the middle or late stage, or it will take several years to progress to the middle or late stage.