Most of the malignant tumor patients are already in advanced stage when they are diagnosed and have lost the opportunity of surgery, before the targeted drugs entered the clinical application in the last century, they can only take chemotherapy as the main comprehensive treatment, but for most of the malignant tumors, the efficiency of chemotherapy is only 20%-40%, and even for the patients who are initially effective in chemotherapy, they will eventually relapse due to drug resistance, and the improvement of chemotherapy on survival is not obvious. The median survival is only about 12 months, and the 5-year survival rate is only 14%-20%, so the prognosis of patients is poor. In addition, chemotherapy drugs have many drawbacks and toxic side effects, and even forced to stop treatment due to some serious adverse reactions. The most serious and high incidence of these reactions include bone marrow suppression and gastrointestinal toxicity. Most chemotherapeutic drugs have varying degrees of myelosuppression, resulting in a decrease in white blood cells, especially granulocytes, and in severe cases, platelets, red blood cells, and hemoglobin, causing fatigue, decreased resistance, infection, fever, and bleeding in patients. Another more serious toxicity is gastrointestinal reactions. Most patients will experience loss of appetite, nausea, vomiting and dry mouth during chemotherapy, and sometimes oral mucositis or ulcers or constipation, paralytic intestinal obstruction, diarrhea, gastrointestinal bleeding and abdominal pain, etc. Severe gastrointestinal reactions may even cause chemoresistance in some patients. Other side effects include immunosuppression, nephrotoxicity, liver damage, cardiotoxicity, pulmonary toxicity, neurotoxicity, hair loss, such as hearing loss, rash, facial or skin flushing, nail deformation, osteoporosis, bladder and urethral irritation, infertility, amenorrhea, sexual dysfunction, male breast enlargement, etc., which seriously affect the quality of life of cancer patients. Secondly, most chemotherapeutic drugs need to be injected intravenously, which not only prolongs patients’ hospital stay and keeps them in a more depressing environment like hospital for a long time, but more importantly, some of the more irritating chemotherapeutic drugs can cause serious local reactions when injected intravenously, including phlebitis, local tissue necrosis or ulcers that do not heal for a long time, causing great distress to patients. In order to reduce the resistance of chemotherapy drugs, improve the efficacy of cancer treatment, and overcome the toxic side effects of chemotherapy and improve the quality of life of patients, scientists have discovered a new therapy for tumors in the continuous exploration of —- targeted therapy, the emergence of targeted therapy has opened up a new field and a broad prospect for the treatment of tumors. This treatment method can limit the therapeutic effect or drug effect to specific target cells, tissues or organs as much as possible without affecting the function of normal cells, tissues or organs, so as to improve the efficacy and reduce the toxic side effects. The high efficiency, low toxicity and convenience of targeted therapies have brought benefits to patients, the most important of which is molecularly targeted therapy. Molecular targeted therapy refers to the use of small molecule compounds, monoclonal antibodies, peptides and other substances to specifically interfere with the signaling pathways that regulate the biological behavior of tumor cells, thereby inhibiting tumor development. Targeted therapies are designed to target the identified cancer-causing sites, and the drugs enter the body to specifically select the cancer-causing sites for combined action, resulting in the specific death of tumor cells without affecting the normal tissue cells around the tumor. Therefore, molecular targeted therapy is also called “biological missile”. Clinical practice proves that molecular targeted therapy can not only “kill tumor”, but also induce differentiation of tumor cells to normal cells and “cure tumor”, or “survive with tumor” by inhibiting oncogene signal and delaying tumor development, which may transform malignant tumor into chronic diseases similar to diabetes and hypertension in the future. According to the nature of molecular targeting drugs, molecular targeting drugs can be divided into monoclonal antibodies and small molecule targeting drugs. Small molecule targeted drugs are usually signal transduction inhibitors, which can specifically block the signaling pathways necessary for the growth and proliferation of tumors, so as to achieve the purpose of treatment. Gefitinib is a selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor indicated for the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC) that has received prior chemotherapy or is not amenable to chemotherapy. Gefitinib has a rapid onset of action, resulting in symptomatic remission in an average of 8 to 10 days of dosing. Studies have confirmed that gefitinib has significant efficacy in patients with NSCLC in the presence of EGFR gene mutations. If effective, most are demonstrated by 1 month of dosing. Clinical trials have shown that eastern populations, including China, are more receptive to gefitinib and that the treatment effect is more pronounced. A preliminary analysis of an international multicenter clinical trial of gefitinib to extend survival in lung cancer patients showed that the median survival of the participating Eastern population was 4 months longer, almost twice as long as the other subject groups. Published clinical data from Japanese patients showed that gefitinib resulted in significant tumor shrinkage or stabilization in about half of the lung cancer patients and symptomatic improvement in about half of the patients on the drug. Published treatments from other Asian countries and regions (including China, Taiwan, and Korea) have shown that gefitinib has significantly better overall survival and remission rates in Eastern populations than in Western populations. A study in Korea reported an objective response rate of 25% and a disease control rate of 47.5%, with women, non-smokers and adenocarcinoma patients having a higher response rate to gefitinib. 2. Erlotinib Erlotinib trade name Troche is a tyrosine kinase inhibitor that selectively acts on the epidermal growth factor receptor and is used in the second and third line treatment of non-small cell lung cancer after chemotherapy failure. Erlotinib adverse effects can be tolerated and can significantly prolong the survival and improve the quality of life of patients with advanced or metastatic NSCLC. Sorafenib Sorafenib is a novel multi-targeted antitumor drug with dual antitumor effects, which can inhibit tumor growth directly by inhibiting RAF/MEK/ERK signaling pathway, and indirectly inhibit tumor cell growth by blocking tumor neovascularization through inhibiting VEGF and platelet-derived growth factor receptors. Clinical studies have shown that treatment with sorafenib can prolong the survival time of patients with hepatocellular carcinoma and kidney cancer, and the US FDA has approved its use for the treatment of unresectable hepatocellular carcinoma and advanced kidney cancer. 4.Sunitinib is a novel indolone drug, a selective multi-target tyrosine kinase inhibitor, which inhibits the activity of vascular endothelial growth factor receptors-1, 2 and 3, platelet-derived growth factor receptors-α and β, and also inhibits the activity of several other related tyrosine kinases, and has both anti-tumor activity and anti-angiogenic effect. It mainly treats gastrointestinal mesenchymal tumor and advanced renal cell cancer, and has inhibitory effect on many kinds of tumors because it is a multi-target tyrosine kinase inhibitor. 5.Apatinib Apatinib is the world’s first small molecule anti-angiogenic targeted drug proven to be safe and effective in advanced gastric cancer, and is also a single drug that significantly prolongs survival after standard chemotherapy fails in advanced gastric cancer. At the same time, it is the only oral agent among targeted drugs for gastric cancer, which can effectively improve patients’ compliance with treatment and significantly reduce treatment cost. 6.Crizotinib Most of the malignant tumor patients are already in advanced stage when diagnosed and have lost the chance of surgery, before the targeted drugs entered the clinical application in the last century, they can only take chemotherapy-based comprehensive treatment, but the efficiency of chemotherapy is only 20%-40% for most of the malignant tumors. The median survival is only about 12 months, and the 5-year survival rate is only 14%-20%, so the prognosis of patients is poor. Moreover, chemotherapy drugs themselves have many disadvantages and toxic side effects, and even forced to stop treatment due to some serious adverse reactions. The most serious and high incidence of these reactions include bone marrow suppression and gastrointestinal toxicity. Most chemotherapeutic drugs have varying degrees of myelosuppression, resulting in a decrease in white blood cells, especially granulocytes, and in severe cases, platelets, red blood cells, and hemoglobin, causing fatigue, decreased resistance, infection, fever, and bleeding in patients. Another more serious toxicity is gastrointestinal reactions. Most patients will experience loss of appetite, nausea, vomiting and dry mouth during chemotherapy, and sometimes oral mucositis or ulcers or constipation, paralytic intestinal obstruction, diarrhea, gastrointestinal bleeding and abdominal pain, etc. Severe gastrointestinal reactions may even cause chemoresistance in some patients. Other side effects include immunosuppression, nephrotoxicity, liver damage, cardiotoxicity, pulmonary toxicity, neurotoxicity, hair loss, such as hearing loss, rash, facial or skin flushing, nail deformation, osteoporosis, bladder and urethral irritation, infertility, amenorrhea, sexual dysfunction, male breast enlargement, etc., which seriously affect the quality of life of cancer patients. Secondly, most chemotherapeutic drugs need to be injected intravenously, which not only prolongs patients’ hospital stay and keeps them in a more depressing environment like hospital for a long time, but more importantly, some of the more irritating chemotherapeutic drugs can cause serious local reactions when injected intravenously, including phlebitis, local tissue necrosis or ulcers that do not heal for a long time, causing great distress to patients. In order to reduce the resistance of chemotherapy drugs, improve the efficacy of cancer treatment, and overcome the toxic side effects of chemotherapy and improve the quality of life of patients, scientists have discovered a new therapy for tumors in the continuous exploration of —- targeted therapy, the emergence of targeted therapy has opened up a new field and a broad prospect for the treatment of tumors. This treatment method can limit the therapeutic effect or drug effect to specific target cells, tissues or organs as much as possible without affecting the function of normal cells, tissues or organs, so as to improve the efficacy and reduce the toxic side effects. The high efficiency, low toxicity and convenience of targeted therapies have brought benefits to patients, the most important of which is molecularly targeted therapy. Molecular targeted therapy refers to the use of small molecule compounds, monoclonal antibodies, peptides and other substances to specifically interfere with the signaling pathways that regulate the biological behavior of tumor cells, thereby inhibiting tumor development. Targeted therapies are designed to target the identified cancer-causing sites, and the drugs enter the body to specifically select the cancer-causing sites for combined action, resulting in the specific death of tumor cells without affecting the normal tissue cells around the tumor. Therefore, molecular targeted therapy is also called “biological missile”. Clinical practice proves that molecular targeted therapy can not only “kill tumor”, but also induce differentiation of tumor cells to normal cells and “cure tumor”, or “survive with tumor” by inhibiting oncogene signal and delaying tumor development, which may transform malignant tumor into chronic diseases similar to diabetes and hypertension in the future. According to the nature of molecular targeting drugs can be divided into monoclonal antibodies and small molecule targeting drugs. Second, monoclonal antibodies Monoclonal antibody is an antibody against a specific antigen, with the ability to target and kill the antigen. Monoclonal antibodies have highly homogeneous properties. 1.Bevacizumab Bevacizumab for recombinant humanized anti-VEGF monoclonal antibodies, can be closed by VEGF and block its binding with VEGFR, so that VEGFR can not be activated and play an anti-angiogenic effect, its treatment of tumors with good results. Currently, the FDA has approved bevacizumab for the first-line treatment of metastatic colorectal cancer, metastatic breast cancer, advanced non-small cell lung cancer, and metastatic renal cell cancer. In addition, the application of bevacizumab in other malignancies such as liver cancer, gastric cancer and esophageal cancer has also achieved encouraging results. Trials have shown that rational chemotherapy combined with bevacizumab-targeted therapy not only improves the efficiency but also significantly prolongs the median survival without increasing the overall adverse effects. For elderly patients, bevacizumab therapy has a high safety profile. 2. Cetuximab Cetuximab specifically binds to EGF receptors expressed on the surface of normal cells and a variety of cancer cells, and competitively blocks the binding of EGF and other ligands, such as alpha transforming growth factor (TGF-α). Cetuximab is an IgG1 monoclonal antibody against the EGF receptor, and upon specific binding of the two, it blocks intracellular signaling pathways by inhibiting the tyrosine kinase (TKI) that binds to the EGF receptor, thereby inhibiting the proliferation of cancer cells, inducing apoptosis, and reducing the production of matrix metalloproteinases and vascular endothelial growth factor. Currently, cetuximab is approved for the treatment of metastatic colorectal cancer, non-small cell lung cancer and head and neck tumors. Studies have shown that treatment with cetuximab in combination with irinotecan regimens significantly prolonged overall survival (median overall survival of 23, 5 and 20 months, respectively) and progression-free survival (9, 9 and 8, 4 months, respectively) and significantly increased overall remission rates (57, 3% and 39, 7%, respectively) in patients with K-ras wild-type metastatic colorectal cancer. Cetuximab in combination with standard first-line chemotherapy regimens has emerged as an important new treatment option for patients with K-ras wild-type colorectal cancer. 3. Trastuzumab Trastuzumab is a recombinant humanized monoclonal antibody that specifically binds to the HER2 receptor and affects its growth signaling, promotes the internalized degradation of HER2 receptor protein, and attacks and kills tumor cells through antibody-dependent cell-mediated cytotoxicity. In addition, trastuzumab down-regulates the activity of vascular endothelial growth factor and other vascular growth factors. Trastuzumab was approved by the FDA in September 1998 for the treatment of HER2-positive breast cancer patients. 5 large clinical studies enrolled more than 13,000 patients and compared the difference between adjuvant treatment with and without trastuzumab and between 1 and 2 years of adjuvant treatment with trastuzumab. The results showed that 1 year of adjuvant treatment with trastuzumab reduced the relative risk of breast cancer recurrence by 46% to 52% and the relative risk of death by approximately 33%. In addition, HER2 expression in patients with gastric cancer amounted to 22, 1%. An international multicenter phase III clinical trial showed that chemotherapy plus trastuzumab treatment significantly improved the remission rate (47, 3% and 34, 5%, respectively) and overall survival time (13, 5 and 11, 1 months, respectively) in HER2-positive patients with progressive gastric cancer. The results of this trial make more treatment options available for patients with HER2 high expression gastric cancer and will become a new standard for individualized treatment of gastric cancer. 4.Rituximab Rituximab is the first monoclonal antibody used in clinical practice, is a human-mouse chimeric monoclonal antibody to CD20, which exerts anti-tumor effects by binding to CD20 expressed on B cells and B-cell lymphoma cells, via antibody-dependent cytotoxic effects and complement-dependent cytotoxic effects, etc. The US FDA has approved it for the first-line treatment of CD20-positive diffuse large B The FDA has approved it for the first-line treatment of CD20-positive diffuse large B-cell non-Hodgkin’s lymphoma and follicular non-Hodgkin’s lymphoma. A multicenter, open, single-arm clinical study showed that the combination of rituximab and vincristine + doxorubicin + cyclophosphamide + prednisone regimen for the treatment of diffuse large B-cell non-Hodgkin’s lymphoma resulted in a 76% remission rate (including a 59% complete remission rate), a 2-year tumor-free survival rate and an overall survival rate of 65,5% and 68,5%, respectively. Other CD-targeted agents include gituzumab, which targets CD33, and alemtuzumab, which targets CD52, for acute myeloid leukemia and refractory chronic lymphocytic leukemia, respectively. There are also panitumumab and nitrozumab, which are used to treat patients with metastatic colorectal cancer and epidermal growth factor receptor-positive advanced nasopharyngeal cancer, respectively.