At present, only about 1/3 of cancer patients in China can be cured, and the majority of them are early-stage cancers, for example, the five-year survival rate after treatment for early-stage nasopharyngeal carcinoma is over 90%, while less than 40% for advanced-stage patients. Therefore, any reason of delaying cancer treatment will lead to the reduction of cancer treatment effect. There are many reasons for delaying cancer treatment, from the patient’s side, the doctor’s side, and the cancer itself. Patients lack awareness of the symptoms of cancer, are paralyzed or do not take it seriously, and only when the cancer becomes advanced and serious symptoms appear, do they seek treatment in the hospital, missing the good opportunity for treatment. Doctors who receive cancer patients for the first time are often not oncologists, and due to inexperience or lack of vigilance, they may easily miss or misdiagnose the cancer, resulting in the development of advanced stage cancer. In some cancers, there are no symptoms at all in the early stage, but they are already in advanced stage when symptoms appear, such as liver cancer. Therefore, the reasons for delayed treatment of cancer are complicated. At present, the treatment effect of late stage cancer is still very unsatisfactory, firstly, because of the large size of tumors, which often invade the adjacent important organs or tissues such as heart or large blood vessels and lose the opportunity of surgical removal. Secondly, larger tumors are less sensitive to radiotherapy or chemotherapy, and the treatment effect is not good. Again, the longer the course of cancer, the more advanced the disease, the greater the chance of distant metastasis. Once metastasis occurs, the treatment effect is very poor and there is no special treatment method. Finally, patients with advanced cancer are often very weak, even skin and bones, and cannot withstand surgery, radiotherapy or chemotherapy, which limits the anti-cancer treatment. Based on the above reasons, the relevant departments should vigorously carry out the propaganda of cancer prevention knowledge so that the public can understand some early signs of cancer occurrence. Once found, they should immediately go to hospitals, especially oncology hospitals, for early detection, early diagnosis and early treatment, so as to obtain good treatment effect, instead of seeking medical help in a hurry or trusting doctors, so as not to delay the disease and miss the opportunity to cure it.