Chemotherapy is one of the important means of treating malignant tumors at present, and efforts to individualize chemotherapy regimen and maximize the effect of chemotherapy have attracted more and more attention of clinicians. The Department of Oncology of PLA 304 Hospital has carried out the individualized treatment of malignant tumors under the guidance of in vitro tumor cell culture plus adenosine triphosphate biofluorescence method and drug sensitivity test, which has achieved good therapeutic effect and reduced the blindness of chemotherapy. 1, chemotherapy in tumor treatment occupies a very important position Malignant tumors are common and frequent diseases that seriously endanger human life and health, and are one of the main diseases leading to disability and early death, and malignant tumors are the first cause of death in the age group of 35-59 years old. At present, the world’s main treatments for malignant tumors include surgery, radiotherapy, chemotherapy, endocrine therapy and bioimmunotherapy. Among the many means of malignant tumor treatment, chemotherapy, as a systemic treatment method, has the possibility to kill the tumor cells in the patient’s body to the maximum extent compared with other methods, therefore, chemotherapy occupies a very important position in the treatment of malignant tumors. With the development of medicine, chemotherapy is no longer a mere palliative treatment, but is in transition from palliation to radical treatment. Chemotherapy plays a palliative therapeutic role in some advanced tumors, such as prolonging patients’ life, alleviating symptoms and reducing pain, for example, gastric cancer, esophageal cancer, non-small-cell lung cancer, head and neck cancer, renal cancer, melanoma, prostate cancer, endometrial cancer and so on. Factors affecting the efficacy of chemotherapy Although chemotherapy occupies a very important position in the treatment of malignant tumors, in clinical practice, the results are often unsatisfactory. Among them, drug resistance of tumor cells to chemotherapeutic drugs is a common factor leading to the failure of tumor chemotherapy, and is also a key problem plaguing tumor treatment. Drug resistance is an extremely common clinical problem, and the American Cancer Society estimates that more than 90% of patients who die from tumors are affected by drug resistance to varying degrees. Tumor cell resistance is divided into two major categories: primary and acquired resistance. Tumors are a heterogeneous, polymorphic population of cells with varying degrees of differentiation. There are obvious individual differences in tumor resistance to various chemotherapeutic agents. That is, different tumor types or different patients of the same type, or even the same patient at different stages of development, do not have exactly the same sensitivity to chemotherapy, and the therapeutic effects vary greatly. So far, there is no chemotherapeutic drug or combination of several chemotherapeutic drugs that can be 100% effective for a certain type of tumor. For this reason, it is necessary to establish a relatively reliable sensitivity test method, like bacterial sensitivity test, to accurately screen sensitive chemotherapeutic drugs for different patients and determine their dosages, so as to truly realize the individualization of clinical medication. Advantages of individualized chemotherapy under the guidance of drug sensitivity In recent years, with the progress of molecular and cell biology research, scholars at home and abroad are constantly searching for simple, easy, accurate and reliable sensitivity testing methods for chemotherapy drugs, and at present, we have created two major series of in vivo and in vitro sensitivity test methods with more than 10 kinds of sensitivity test methods. Among them, primary tumor cell culture is one of the most ideal drug sensitivity test methods so far. This method is characterized by the culture of fresh tumor tissues obtained directly from the patient’s body – since the tumor cells have just been removed from the body, their biological properties have not yet undergone major changes, so it can more truly reflect the characteristics of the entire tumor cell population and the individual differences of different donors, and can more accurately represent the in vivo state.