1. For patients, their general condition is too poor and their vital organs are not fully functional to tolerate sufficient doses of anti-tumor therapy. Therefore, patients need to stop the treatment before the efficacy appears, which is not worth the loss; some patients cannot cooperate and are eager for success. Some patients cannot cooperate and are in a hurry. They do not observe the best effect of drugs and ask for drug change. 2. On the side of tumor, primary or secondary drug resistance; low proliferation ratio of tumor; the area where tumor is located (the so-called “refuge”) is inaccessible or difficult for drugs to enter. 3. Physicians fail to decide the treatment according to the treatment specification according to the indications of medical treatment; improper selection of drugs and programs, especially endocrine and targeted therapy, unknown or improper receptors and gene expression of drug action; failure to deal with adverse drug reactions appropriately; improper route of drug administration leading to treatment failure; lack of understanding of comprehensive treatment and failure to grasp the opportunity to continue medical treatment when other treatment means should be taken. opportunities, etc.