To improve the 5-year survival rate of lung cancer, the key is early diagnosis and proper comprehensive treatment. Early diagnosis of lung cancer is extremely important, and early detection is the key to improve the cure rate. How to achieve early detection? 1.It is necessary to conduct lung cancer screening for middle-aged or high-risk groups (long-term smokers, long-term exposure to radioactive substances or those with family history of tumor), and chest X-ray examination (chest fluoroscopy or chest X-ray radiography) should be conducted every six months to a year. 2. Be alert to early symptoms of lung cancer with cough as the first symptom accounts for about 60% or more. Because the tumor (e.g. central lung cancer) grows on the bronchial mucosa, foreign body sensation can occur and coughing can occur. Typically, it is a paroxysmal irritating choking cough with a small amount of white mucous sputum. People often mistake this symptom as bronchitis or smoking, and fail to treat it early enough to delay the diagnosis. When treatment for bronchitis is ineffective, we must be vigilant. 3.Blood in sputum or hemoptysis can occur in lung cancer and many other lung diseases. Hemoptysis accounts for about 35% of lung cancer, and is mostly persistent or intermittent with repeated small amounts of hemoptysis, or occasionally with large hemoptysis. It is especially important to note that occasional hemoptysis is often confused with other lung diseases, such as bronchiectasis, so sputum examination for tumor cells should be done to differentiate. This is an easy, safe, painless and valuable diagnostic method. The method is to cough up the sputum from the deep part of the lung (do not mix with saliva and nasal mucus), and leave one or two mouths of fresh sputum (preferably blood sputum, gray sputum or clear mucus sputum) to hospital for cytological examination, and the positive rate can be more than 80%. 4. Pay attention to repeated infections in the same area Repeated inflammation in the same area (such as a certain lobe or lung segment) should alert the possibility of lung cancer. Because the tumor is blocking the bronchial lumen in the development, the secretion retention can cause pneumonia secondary to infection. At this time, anti-inflammatory treatment is effective, symptoms disappear and lung cancer shadow can be absorbed, but it often occurs repeatedly. After anti-inflammatory treatment, fiberoptic bronchoscopy should be performed to understand the condition of bronchus belonging to the site of recurrent pneumonia. Patients with lung cancer can have some extra-pulmonary symptoms and signs, which should be alerted. Some patients even use extra-pulmonary symptoms and signs as the first symptoms of lung cancer. These extra-pulmonary symptoms are not caused by direct infiltration of cancer foci inside the lung or metastasis of lung cancer, but by some special hormones, antigens and enzymes produced by lung cancer. For example, Cushing’s syndrome, osteoarthrosis and pestle finger (toe), dermatomyositis, acanthosis nigricans, myasthenia gravis syndrome, hyponatremia and hypoglycemia. Paying high attention to these extra-pulmonary manifestations of lung cancer can help the diagnosis of dry lung cancer. Early lung cancer treatment is effective. Early diagnosis and early formal treatment are important, and it is important not to seek medical help when there is a disease.