1.What is targeted therapy? Targeted therapy mainly targets the tumor-specific pathogenesis or signaling pathways, and uses monoclonal antibodies or small molecules to interfere or block it, so as to achieve the purpose of treating tumors. Targeted therapy is highly specific, safe and well tolerated, and common side effects of chemotherapy, such as hair loss, nausea and vomiting, and bone marrow transplantation, occur less frequently. 2.How many kinds of targeted therapies are commonly used for lung cancer? What are the representative drugs? The first category is small molecules that act on tumor cell signaling pathways, commonly known as tumor epidermal growth factor receptor inhibitors, and the representative drugs include ERSA (Gefitinib) and Troche (Erlotinib). The second category is for tumor angiogenesis, including anti-vascular endothelial growth factor monoclonal antibodies and vascular endothelial inhibitors. The representative drug of the former is Avastin, and the representative drug of the latter is Endostar. 3.How long does targeted therapy need to be applied? Generally, for advanced patients, if the tumor is in remission or stable after applying targeted therapy, it should be applied for a long time, unless the disease progresses or serious toxic side effects that are hard to tolerate occur. 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 The common toxic side effects of ERSA and Tricor are acne-like rash, diarrhea, itching, dry skin, and mild loss of appetite in a few patients, usually seen within one month after taking the drug. A very small percentage of patients develop interstitial lung disease after receiving either of these drugs, manifesting as cough, chest tightness, and dyspnea, which should be discontinued as soon as the diagnosis is confirmed. The most serious adverse reactions are tumor-related bleeding such as hemoptysis. Can targeted therapy be used simultaneously with chemotherapy? 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.