At this stage, among the top ten malignant tumors in China, lung cancer has replaced liver cancer as the first cause of death from malignant tumors in China, rising 465% over the past 30 years and accounting for 22.7% of all deaths from malignant tumors. In the past, lung cancer tended to be more common in older, smoking, men, but today, the trend of lung cancer increasing in modern women is rather faster than men. The accelerated growth trend of lung cancer in women may be closely related to the increased number of modern women who smoke, the younger age of smoking, passive smoking in women, and more exposure to kitchen fumes in women. If lung cancer can be detected early, its cure rate is not low. The 5-year survival rate of stage I lung cancer can reach about 60%~80%, and the 5-year survival rate of stage II lung cancer can reach 40%~50%. However, due to the high concealment of early symptoms of lung cancer, about 70% of patients with non-small cell lung cancer are already in advanced local stage or have metastasis when they are detected. Currently, the treatment of lung cancer is mainly based on surgery and traditional chemotherapy, but in terms of advanced lung cancer treatment, traditional chemotherapy has reached a plateau with an average survival rate of only 40% at 1 year worldwide. Molecular targeted therapy has been clinically proven to be an effective treatment tool. In the past, once chemotherapy failed, patients often gave up. As a new class of treatment, the unique advantages of molecular targeted therapy in terms of efficacy and good safety have brought great hope to patients with advanced lung cancer. Targeted therapy is mainly used for second and third-line treatment for those who failed in first-line treatment, with higher safety and better quality of life for patients. In addition, targeted therapy is also available for elderly people, patients with locally advanced lung cancer, and some people with poorer constitution who are not suitable for chemotherapy or unwilling to receive chemotherapy. Molecular targeted therapy has opened up a brand new era for the treatment of malignant tumors, especially lung cancer. Targeted action on tumor cells inhibits their growth and proliferation, thus stopping the growth of tumor cells, which not only delays the deterioration of lung cancer-related symptoms such as cough, dyspnea and pain, but also avoids strong side effects such as white blood cell drop, nausea and vomiting caused by traditional chemotherapy, and only needs to be taken orally once a day, significantly improve the quality of life of patients. For eligible patients, the combination of traditional chemotherapy and molecular targeted drug therapy is preferred, and even in some treatment regimens for lung cancer, only molecular targeted therapy is used instead of traditional chemotherapy. However, the prerequisite is that the patient is eligible for targeted therapy (positive genetic test result for EGFR) on the one hand, and is financially secure and can afford the high cost of targeted therapy on the other hand.