What is molecular targeted therapy? Targeted therapy is to design the corresponding therapeutic drugs at the cellular molecular level, targeting the identified oncogenic site (the site can be a protein molecule or a gene fragment inside the tumor cell). Therefore, molecular targeted therapy is also called “biological missile”. For example, epidermal growth factor receptor can regulate cell growth, differentiation, angiogenesis and apoptosis, which are closely related to the growth, invasion and metastasis of malignant tumors. Then we can design drugs to inhibit the epidermal growth factor receptor and thus inhibit the growth and metastasis of tumors. In layman’s terms, it is like a soldier shooting at a target in a playground, with a fixed target and a gun to shoot at it. Therefore, the precision of molecular targeted drug therapy is very high, and it is “targeted”. In recent years, the progress of molecular targeted drug therapy for tumors has entered a brand new era with the development of molecular biology technology and further understanding of the pathogenesis from cellular and molecular levels. The progress in these fields has been rapid, and good results have been achieved in clinical practice. According to the target and nature of drug action, the main molecularly targeted therapeutics can be divided into the following categories: 1. Epidermal growth factor receptor blockers with targeting, such as gefitinib, erlotinib. Epidermal growth factor receptor itself has tyrosinase kinase activity, once combined with epidermal growth factor can initiate the relevant genes in the cell nucleus, thus promoting cell division and proliferation. Epidermal growth factor receptor expression is increased in gastric, breast, bladder and head and neck squamous cancers. Epidermal growth factor receptor blockers inhibit tumor growth by blocking the tyrosine kinase signaling pathway. 2. Monoclonal antibodies against certain specific cellular markers, such as Epiduo, can specifically bind to EGF receptors expressed on the surface of normal cells and many cancer cells, and competitively block the binding of EGF and other ligands, such as α-transforming growth factor. It is a monoclonal antibody against the epithelial growth factor receptor. When the two specifically bind, it blocks the intracellular signal transduction pathway by inhibiting the tyrosine kinase that binds to the epithelial growth factor receptor, thereby inhibiting the proliferation of cancer cells, inducing apoptosis, and reducing the production of matrix metalloproteinases and vascular endothelial growth factor. Monoclonal antibodies against the proto-oncogene human epidermal growth factor receptor 2 gene, such as Herceptin, inhibit the proliferation of tumor cells that overexpress the proto-oncogene human epidermal growth factor receptor 2 gene. For example, breast cancer patients with overexpression of the anti-proto-oncogene human epidermal growth factor receptor 2 gene. Tumor vascularity is inseparable from the occurrence and metastasis of tumor. Tumor vascularity provides nutrients to tumor and creates conditions for tumor growth and metastasis, therefore, inhibiting tumor angiogenesis is also an effective way of anti-tumor. For example, recombinant human vascular endothelial inhibitor injection — “Endo”. “Endo” is a new biological product of vasopressor class with broad-spectrum anti-angiogenic activity. Its mechanism of action is to inhibit tumor neovascularization by inhibiting the migration of endothelial cells that form blood vessels, blocking the supply of nutrients to tumors, and thus inhibiting tumor proliferation or metastasis. Advantages and disadvantages of molecular targeted drug therapy Advantages: 1. Good efficacy Past clinical trials have confirmed that molecular targeted drug therapy can relieve clinical symptoms and prolong survival of tumor patients; some studies have also shown that targeted therapy is expected to delay tumor progression when used as maintenance therapy after chemotherapy. It can add an effective treatment means to chemotherapy or radiotherapy alone, thus making the treatment effect of certain tumors better. Molecular targeted drug 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, which basically has no great effect on normal cells. Molecular targeted drug therapy is characterized by very strong specificity, targeting only cancer cells, so it is safer and better tolerated, and most of the side effects caused by it are reversible, which is a good choice for old and frail patients, as well as patients who cannot tolerate chemotherapy. 3, better quality of life Targeted therapy because of the small side effects, and a lot of oral medication, so the pain is small, easy to take, normal life is basically unaffected, as long as the home according to the doctor’s orders to take medication, regular review on the line. Disadvantages: 1. Single target The targeted drugs currently used in clinical practice can only act on a single target, which simply means that they can only act on one point, while the tumor growth, infiltration and metastasis are multi-pathways as confirmed by the medical profession. Therefore, the effect of molecular targeted therapy drugs alone in controlling tumor is still limited. The cost of molecular targeted therapy is high, which is a heavy burden for tumor patients and their families who need long-term medication, and not every tumor patient and their families can afford it.