1.Targeted therapy challenges traditional treatment Traditional anti-cancer drug therapy mostly uses cytotoxic drugs. As the name implies, they are toxic to many kinds of cells in the body, but they may have a greater effect on cancer cells, which are fast proliferating and dividing, so normal cells in the body are inevitably affected. In contrast, targeted therapy is aimed at one or several targets in tumor cells to inhibit the proliferation of tumor cells. If we take war as an analogy, if chemotherapy is indiscriminate bombing, then targeted therapy is laser-guided precise targeted bombing. In recent years, the emergence of molecular targeted drugs has opened up a brand new era for tumor treatment. While improving the efficacy, it can significantly reduce the risk of side effects and also significantly improve the quality of life of patients, representing the future trend of tumor treatment. The most successful example of molecular targeted therapy is Imatinib mesylate (Gleevec). It is a selective inhibitor of Bcr-Abl tyrosine kinase. Whether in the chronic, progressive or acute phase of chronic granulocytic leukemia, imatinib has shown convincing therapeutic efficacy and has delivered a powerful impact on the treatment of chronic granulocytic leukemia. Imatinib’s role in gastrointestinal mesenchymal sarcoma – a highly chemo-radiotherapy resistant solid tumor – is also impressive, achieving an excellence never before achieved in its history. Bevacizumab, a humanized monoclonal antibody against VEGF, has shown efficacy in the treatment of advanced colorectal cancer. Cetuximab was the first IgG1 monoclonal antibody specifically targeting EGFR to be approved for marketing. In 2004, the FDA approved cetuximab in combination with irinotecan for recurrent or metastatic colorectal cancer that is EGFR expression positive and has failed or is resistant to irinotecan therapy, or monotherapy for those who cannot tolerate chemotherapy. In addition, cetuximab has also shown better anti-tumor effects in the treatment of advanced head and neck squamous carcinoma. 3.Molecular targeted therapy cannot replace traditional chemotherapy Although traditional chemotherapy has many shortcomings, with the development of adjuvant therapy drugs, chemotherapy reactions are not as horrible as people think. Moreover, in terms of efficacy, traditional chemotherapy is better than targeted drugs in terms of efficiency, median survival and other indicators. Therefore, from the current clinical treatment level, targeted therapy cannot replace traditional chemotherapy yet. Although molecular targeted therapy cannot replace traditional treatment such as surgery, radiotherapy and chemotherapy at this stage, its significant meaning is that it can make the treatment more targeted and better individualize the treatment. It can be used as a new means of treatment for patients who have failed chemotherapy, and targeted therapy can also be the first choice of treatment for the elderly and patients with poor physical condition. As long as the patients are selected appropriately, its efficacy can break through people’s imagination. 4.Commonly used targeted therapeutic drugs Molecular targeted therapy is an extremely important part of tumor biotherapy, and can be said to be the most promising and practical part of tumor biotherapy at present. At present, more than 20 molecular targeted therapeutics have been approved by FDA for clinical treatment of various hematologic tumors and solid tumors. Name Trade Name Action Target Indication Rituximab Meroval CD20 B-cell lymphoma Alemtuzumab CD52 Chronic lymphocytic leukemia Trastuzumab Herceptin Her-2 Breast cancer Cetuximab Epiduo EGFR Colorectal cancer Bevacizumab Avastin VEGF Colorectal cancer Gefitinib Eressa EGFR tyrosine kinase Non-small cell lung cancer Erlotinib Troche EGFR tyrosine kinase non-small cell lung cancer and pancreatic cancer sorafenib doxorubicin RAF/MEK/ERK signaling pathway; VEGF and PDGF advanced hepatocellular carcinoma and advanced renal cell carcinoma imatinib gleevec bcr-abl tyrosine kinase chronic granulocytic leukemia and gastrointestinal malignant mesenchymal tumor sotan VEGF-R2, -R3 and -R1, PDGFR-β, KIT, FLT-3 and RET of tyrosine kinase advanced kidney cancer and gastrointestinal malignant mesenchymal tumor Vandetanib EGFR, VEGFR and RET tyrosine kinase advanced thyroid cancer Bortezomib Vanco proteasome multiple myeloma Lapatinib EGFR and HER2 tyrosine kinase advanced breast cancer Recombinant human vascular endothelial inhibitor Endo vascular endothelial cell non-small cell lung cancer and others 5. Targeted therapies that still need to be investigated in depth Although targeted therapy brings new hope for tumor patients, the efficiency of most targeted drugs is basically around 10% in the current exploration stage. The reason for this is that most solid tumors are multi-targeted and multi-linked regulatory processes. Therefore, just seeing the overexpression of a single factor and assuming that there must be a functional role for tumor growth is obviously incomplete. Likewise, it is not objective to block one receptor and assume that it blocks any message transmission. In addition, the huge cost of targeted therapy again makes us feel that it is still too far away from the common people.