If conventional chemotherapy is likened to indiscriminate bombing on the battlefield, then targeted therapy is the precision-guided bomb! Targeted therapy kills only cancer cells Research over the years has shown that abnormalities in genes such as oncogenes, oncogenes and growth factors play a rather important role in the occurrence and development of lung cancer. Currently, the discovery of driver genes for lung cancer, especially lung adenocarcinoma, has provided a “target” for lung cancer prevention and treatment, making “precise targeting” a reality. Since then, a new field of lung cancer drugs and methods has been born – targeted lung cancer therapy. Targeted lung cancer therapy means that the drug only acts on tumor cells through the tumor target specifically, and has little or no effect on normal cells, so it only kills tumor cells and does not harm normal cells or rarely. Therefore, it is undoubtedly a very good choice for those patients who cannot tolerate chemotherapy and do not want to receive it. The symptoms can be improved in 7-10 days The mechanism of action of targeted therapy is different from traditional cytotoxic chemotherapy drugs. After entering tumor cells, the drugs of targeted therapy can inhibit the proliferation, infiltration and metastasis of tumor cells and promote apoptosis of tumor cells by acting on the unique structure of tumor. Whether it is targeted therapy or chemotherapy, both are means of systemic treatment for patients, but the difference lies in that when chemotherapy is administered to lung cancer patients, the drugs enter the body and kill tumor cells while normal cells are harmed to a certain extent due to the low selectivity, while targeted therapy does not harm normal cells and may cause less side effects because it has specific targets. Generally speaking, some patients will have mild diarrhea and rash, and some will have interstitial pneumonia. In addition, the effect of targeted therapies is usually very fast, with an average of 7-10 days to see the improvement of symptoms, and the patient’s health and quality of life can be significantly improved soon. When to use targeted therapy Since it is called targeted therapy, the existence of a “target” is a prerequisite for the use of targeted drugs. It should not be used without a clear target because of its high efficiency and low side effects. This will not only be ineffective, but may also delay the regular treatment and bring serious consequences. Of course, the high cost has also been a major reason why many patients are discouraged from targeted therapy, many patients have to delay until other treatments are ineffective before they think about it, but the final outcome is that money is not less spent, and life is not extended for a long time. Therefore, the sooner patients use targeted therapy after the indications are clear, the more benefits it may be for them. Currently used targeted drugs for lung cancer 1. Gefitinib (Gefitinib , Iressa, Eressa): It is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) and is the first molecularly targeted drug for lung cancer to enter clinical studies. First-line treatment for EGFR mutations is up to 70%-90% effective. The recommended dose is 250 mg (1 tablet) once daily. The most common adverse drug reactions (ADRs) are diarrhea, rash, pruritus, dry skin, and acne, with an incidence of 20% or more, usually within one month of taking the drug, and usually reversible. 2. Erlotinib (Erlotinib, Tarceva, Troche): is also an EGFR-TKI agent. The recommended dose of Erlotinib alone for non-small cell lung cancer is 150 mg (1 tablet)/day, taken at least 1 hour before or 2 hours after eating. Continue until disease progression or intolerable toxicities occur. There is no evidence that patients benefit from continued treatment after progression. The most common adverse reactions were rash (75%) and diarrhea (54%). They are mostly of degree 1 or 2 and can be managed without interruption of dosing. Erlotinib is also used in the treatment of pancreatic cancer. 3. Crizotinib (Crizotinib, Securitin): is an ALK/c-MET small molecule inhibitor for the treatment of locally advanced and metastatic non-small cell lung cancer that is mesenchymal lymphoma kinase (ALK)-positive. Preliminary epidemiological studies suggest that the ALK positivity rate is approximately 3% to 5% in patients with NSCLC. The most common adverse reactions are visual impairment, nausea, diarrhea, vomiting, edema, and constipation. 4, Afatinib (Gilotrif): A second-generation EGFR-TKI agent, it is an irreversible inhibitor of epidermal growth factor receptor (EGFR) and human epidermal receptor 2 (HER2) tyrosine kinases. It is indicated for the first-line treatment of advanced non-small cell lung cancer (NSCLC) and for patients with HER2-positive advanced breast cancer. The recommended dose is 40 mg orally once daily until disease progression or until not longer tolerated by the patient. Take at least 1 hour before or 2 hours after a meal. The most common toxicities are diarrhea, rash, nausea, hypertension, anorexia, asymptomatic QT interval prolongation and proteinuria. 5. Bevacizumab (Bevacizumab, Avastin, Avastin), the world’s first anti-tumor angiogenesis drug, is a recombinant human monoclonal IgG1 antibody that acts by inhibiting the biological activity of human vascular endothelial growth factor. It can be used to treat metastatic non-small cell lung cancer. Recommended dose: 5mg-7.5mg/kg. The most serious adverse drug reactions are: gastrointestinal perforation; bleeding, including pulmonary hemorrhage/hemoptysis more commonly seen in patients with NSCLC (non-small cell lung cancer); and arterial thromboembolism.