The difference between intermediate and advanced stages of lung cancer is mainly manifested in the following aspects: i. The scope of spread: Intermediate stage of lung cancer refers to the second and third stages of lung cancer development. When lung cancer reaches these two stages, it has already infiltrated the surrounding tissues and metastasized to regional lymph nodes, but there is no distant organ metastasis. And at the advanced stage of lung cancer, the cancer cells have metastasized and spread to distant tissues, and the distribution of cancer tissues is more extensive. Clinical manifestations: Although patients with mid-stage lung cancer have already shown obvious lung cancer symptoms, such as cough, hemoptysis, fever and difficulty in breathing. However, most of these symptoms are limited to the respiratory system where lung cancer is located, and rarely appear in other systems. In contrast, in advanced stage lung cancer, as the cancer cells have spread to other organs, corresponding systemic symptoms will appear, especially symptoms of non-respiratory system such as limb paralysis, coma and jaundice. Treatment options: Most patients with mid-stage lung cancer still have the chance of radical surgery. In contrast, advanced lung cancer generally has no chance of radical surgical treatment. The prognosis is different: the survival period of patients is different. The prognosis of mid-stage lung cancer is better than that of advanced lung cancer patients, and the five-year survival rate of mid-stage lung cancer is generally about 30%, while the five-year survival of advanced lung cancer does not exceed 10%.