According to clinical practice, cancer pain is a sign of disease progression. Since the pressure and damage of malignant tumors on the body’s organs and nervous system can lead to pain, the degree of pain often also indicates the extent of tumor damage to the body’s organs or nerves. Therefore, when patients feel pain worsening, it mostly indicates a new progress of the disease. Also, pain tends to worsen when the tumor recurs or metastasizes. In addition, the most important thing is to go to oncology pain specialist for treatment after pain occurs, and not to think that the pain is not related to cancer, and doctors of other departments may only pay attention to pain and not necessarily pay attention to the tumor, which is more likely to mislead the condition. In fact, cancer pain is fundamentally different from other chronic pain (such as low back and leg pain) because it is related to tumor, and the treatment methods and ideas are also different. Therefore, the pain department of oncology hospitals is more specialized in diagnosing and treating cancer pain as a whole. How does cancer pain affect the patient’s psychology or the treatment effect of cancer? The impact of pain on people is multi-faceted, from the perspective of mental psychology: 1) patients feel poor appetite and reduce the amount of food when they are in pain, which is also the most common reaction; 2) long-term pain will make patients feel restless and meaningless, so they will experience anxiety, depression, self-abandonment, and even suicidal tendency; 3) pain leads to poor sleep, which not only affects the patients’ daily life, but also affects the normal life of their family members; 4) cancer pain will cause the patients to suffer from pain, which will also affect the normal life of the patients. 3. Poor sleep caused by pain not only affects the patient’s daily life, but also affects the normal life of his family members. For example, when the patient suffers from cancer pain and can’t sleep, his family members need to help him locally knead in order to alleviate the pain, and they also need to assist him in turning over, which brings a heavy physical and mental burden to his family members. From the physiological point of view, prolonged poor eating and sleeplessness will lead to a decline in the body’s resistance, and tumor cells generally develop most rapidly when the body’s resistance is poor, which is not conducive to the treatment of cancer. Some foreign studies have found that persistent moderate to severe pain will accelerate the death of patients, and the speed of such death is several times to dozens of times the speed of normal cancer progression. How should I choose between treating malignant tumors and cancer pain? Will cancer pain be relieved as long as the tumor is brought under control? Clinically, many patients believe that as long as the tumor is controlled, the cancer pain will be relieved. Theoretically, since most of the cancer pain is caused by the tumor itself, it is true that if the tumor is cured, the pain will be relieved, and this is also the ultimate goal of clinical treatment. However, there is often a phenomenon in clinic that most of the early stage cancers recover relatively well after surgery and radiotherapy, but the cancers are prone to recurrence, and the tumor cells will be resistant to radiotherapy drugs, which makes it very difficult to carry out the treatment again, and at this time, if we still follow the traditional concept that pain can be relieved when the cancer is cured, it will be not very realistic. Nowadays, the new unanimously accepted viewpoint is that, in treating cancer, pain should be controlled at the same time as soon as pain occurs, and even pain relief is needed in the early stage of tumor treatment. From the comparison between domestic and foreign countries, Chinese people’s concept of treating cancer pain is very different from that of western countries. The morphine consumption in the United States is more than one hundred times of that in China, accounting for more than 40% of the total morphine consumption in the world. Many cancer patients in foreign countries believe that they need to be treated as long as pain occurs, and other anti-tumor treatments are carried out at the same time as pain control; however, Chinese people tend to tolerate pain to treat cancer first, which ultimately leads to patients receiving radiotherapy in the midst of severe pain, which is undoubtedly detrimental to the treatment of cancer. Moreover, some radiotherapy treatments also require active cooperation from patients. For example, radiotherapy requires proper body position, but some patients are unable to cooperate with radiotherapy in the end due to pain-induced restriction of movement. Therefore, the treatment of cancer and cancer pain should be put in the same important position, and the problem of pain should be solved at the same time of active anti-tumor treatment, so that the patients can have the physical ability to receive radiotherapy and have enough resistance to fight against cancer.