1.What is targeted therapy? Traditional chemotherapy or radiotherapy mainly targets the DNA of tumor cells, which often lacks specificity and kills many normal cells at the same time. Targeted therapy is completely different from the previous chemotherapy. The so-called targeted therapy mainly targets the tumor-specific pathogenesis or signaling pathway, and uses monoclonal antibodies or small molecules to interfere or block it, so as to achieve the purpose of treating tumors, but has no great effect on normal cells. The characteristics of targeted therapy are firstly, it is very specific and only targets cancer cells; secondly, it is safe and well tolerated, lacking the common side effects of chemotherapy, not causing patients to lose their hair, not causing patients’ nausea and vomiting, and not causing bone marrow suppression. It can be said that targeted therapy has brought a new revolution in tumor treatment and will become the most promising and promising therapy in tumor treatment in this century. 2.How many kinds of targeted therapies are commonly used in lung cancer? What are the representative drugs? According to the nature and targets of drugs, there are two main types of targeted therapies commonly used in lung cancer treatment as follows. The first category is targeting tumor blood vessels, including anti-vascular endothelial growth factor monoclonal antibodies and vascular endothelial inhibitors. The representative drug of the former is Avastin (Bevacizumab), and the representative drug of the latter is Endostar (China). The second is a small molecule that acts on tumor cell signaling pathway, more common is the tumor epidermal growth factor receptor inhibitor, the representative drugs include ERSA (Gefitinib), Troche (Erlotinib), etc., the clinical application is more common. 3.How long does the targeted therapy need to be applied? Generally speaking, for advanced patients, if the tumor is in remission or stable after the application of targeted therapy, it should be applied for a long time unless the disease progresses or there are serious toxic side effects that are difficult to tolerate. Before and after treatment, there must be an assessment of the efficacy, usually a review at 2 months to determine whether it is a beneficial population and whether it is worthy of further treatment. 4.Common adverse reactions and precautions for targeted therapy Erythropoietin and troche are epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, common toxic side effects are diarrhea, acne-like rash, pruritus, dry skin, the incidence of more than 20%, the incidence of nausea and vomiting 15%, usually seen within one month after taking the drug, usually reversible. A very small percentage of patients develop interstitial lung disease after receiving either of these drugs and should be discontinued as soon as the diagnosis is confirmed. The most serious adverse reactions are tumor-related bleeding, such as hemoptysis or vomiting of blood, so it is prohibited for patients with severe bleeding tendency and squamous lung cancer. 5. Whether targeted therapy can be used simultaneously with traditional Chinese medicine or chemotherapy. Targeted therapy can be used in combination with traditional Chinese medicine, which can reduce some side effects of targeted therapy and may play a synergistic anti-cancer role. Clinically, we have seen some very advanced patients with poor health condition who can turn around after these treatments and maintain their survival for one year, two years or even longer. It should be reminded that they should be applied under the guidance of experienced specialists in regular hospitals. A large number of clinical studies at home and abroad have confirmed that anti-angiogenic targeted drugs such as bevacizumab or Endo can be used in combination with chemotherapy to improve tumor remission rate and long-term survival. However, the combination of small molecules such as eresa or troche with chemotherapy is not advocated, because the research results so far have shown that such combination does not achieve the desired synergistic effect. It is generally recommended to do chemotherapy first and then switch to targeted therapy after chemotherapy is ineffective, which is more prudent.