Research on genes has opened the door to targeted tumor therapy, which has had incredible results in many patients: tumors are controlled, shrunk, and given new access to surgery. However, targeted therapies do not work so well for everyone, why is that? Traditional chemotherapy drugs Drugs have been the conventional means for human to cure diseases, but for a long time drugs lack effective means for mutated tumor cells. The first drugs developed to target tumor cells are actually cytotoxic drugs, which attack tumor cells for their characteristics of growing fast and dividing more. The most commonly used chemotherapeutic drugs have been selected from practice. These, chemotherapeutic drugs have the strongest killing effect on the fast-growing cells, and while killing the fast-growing tumor cells, they also kill some cells in our body that originally grow fast, such as gastrointestinal tract cells, hair follicle cells in hair, and hematopoietic cells. Therefore, vomiting, diarrhea, hair loss, anemia and low resistance are the most common symptoms after chemotherapy with traditional cytotoxic chemotherapy drugs. The so-called molecular targeted therapy is to design the corresponding therapeutic drugs at the cellular molecular level, targeting the mutated genes of tumors, and the drugs selectively destroy these tumor cells with mutated genes, leading to their specific death without destroying the normal tissue cells around the tumors. biological missile”. Traditional chemotherapeutic drugs can be compared to “explosives that do not distinguish between the enemy and the patient”, which have the effect of killing both normal cells and tumor cells, injuring a thousand enemies and damaging eight hundred. On the other hand, molecular targeted drugs can be compared to “missiles that distinguish between the enemy and us”, which can target tumor cells and reduce the damage of chemotherapy drugs to normal cells. With the continuous research and development of molecular targeted drugs and their wide clinical application, the treatment mode of more tumor patients has been converted into chronic lifestyle diseases, similar to the treatment mode of hypertension, diabetes and coronary heart disease, where taking drugs at home can effectively control cancer and even survive with cancer without dying from cancer. Although targeted drugs are effective, they are not effective for everyone because the mutated genes of different patients are different, the same drug that is effective for Zhang San may not work at all for Li Si. The same drug that works for Zhang San may not work at all for Li Si. Why? Because the mutated genes in their bodies are different, so genetic testing should be done to evaluate the expected efficacy of the drug before using it. The reason why targeted therapy is called targeted is that these molecular targeted drugs are designed to target certain mutated genes in tumor cells and to “identify and destroy” these mutated genes, theoretically only tumor cells with these mutated genes can be killed. A targeted drug generally targets only one common mutated gene, but not all tumor patients are mutated in this gene, different tumors and different patients have different mutated genes, therefore, the targeted drug can hurt Zhang San’s tumor cells to avoid accidentally injuring normal tissue cells in human body, while Li Si used it with no effect. This is why there is a wide variety of targeted tumor drugs, so it is especially important to conduct the test for the corresponding gene status first before choosing targeted drug therapy, otherwise it may be ineffective. For example, when taking EGFR-TKI targeted drugs, the efficiency of those who have EGFR gene sensitive mutation is more than ten times higher than those who do not have this gene mutation. The selection of the appropriate molecular targeting drugs after the relevant genetic testing will enable patients to receive accurate and timely individualized treatment, while patients without targeted drugs designed for the gene mutation will avoid accompanying treatment or overtreatment. If patients do not distinguish whether they are suitable for such targeted drugs or not, it is more blind to use targeted drugs when they hear that they are good, which may be lucky and effective to control the disease, but may be ineffective or poor, and the disease still progresses. Although there is still a long way to go for tumor treatment: drug resistance and gene mutation. However, the rational approach at present should be to conduct relevant genetic testing on tumor biopsy or surgically removed tumor tissues and pathological specimens, and then select which chemotherapy drug or molecular targeted therapy drug according to the results of genetic testing, so as to achieve individualized and effective treatment.