There is no basis for the claim that not many patients on chemotherapy can live long. 1, the life expectancy of tumor patients is shorter than that of normal people, and there is also a three-year mortality rate and a five-year mortality rate in medicine to measure the effect of chemotherapy. 2, tumor patients because of the disease itself, it is difficult to live a long time, but this does not mean that chemotherapy has no effect. A large number of clinical practices and researches have confirmed that chemotherapy can significantly extend the life span of a considerable part of patients compared with patients without chemotherapy. 3, due to the limitations of medicine, chemotherapy does not work on all patients, so this part of the patient despite the chemotherapy, not only did not slow down the progress of the disease, but also bring the side effects of chemotherapy to the patient. However, with the development of medicine, these patients are becoming fewer and fewer. Moreover, new drugs keep emerging and there are more and more ways for tumor treatment. So the survival period of tumor patients is getting longer and longer. 4. Research on molecules, genes, proteins and other aspects is constantly progressing, and medical knowledge of tumors is getting deeper and deeper, so as to better screen suitable patients for chemotherapy and obviously improve the effectiveness and precision of chemotherapy. Precision medicine is based on individualized medical treatment, through genome, proteome and other genomics technology and cutting-edge medical technology, the analysis and identification of biomarkers, validation and application of biomarkers for large samples of people and specific types of diseases, so as to accurately search for the target of treatment, and ultimately achieve the purpose of individualized and precise treatment for specific patients, and to improve the efficacy of chemotherapy. The argument that few chemotherapy patients can live long is unfounded. Patients who should be treated with chemotherapy still need to listen to the advice of the attending physician and adhere to the chemotherapy.