The clinical symptoms of Dutch cancer patients do not originate from the cancer cells themselves, but from the accumulation of cancer cells that affect the corresponding organs. When the tissue cells of a certain organ are just cancerous, people will not feel discomfort. When the cancer develops in the form of infiltration and metastasis to the extent that it affects the function of the corresponding organ, various discomforts, i.e. clinical symptoms, will appear depending on the affected organ. Even so, it is not easy to attract attention because some discomfort is easily tolerated or can be relieved by simple symptomatic treatment. At the same time, the sense of localization and pain of human internal organs are relatively dull, which increases the concealment of the occurrence and development of cancerous tissue. When the function of the affected organ is impaired and can barely maintain normal life activities, the clinical symptoms will be more obvious and attract the attention of patients to seek treatment. When the function of the affected organ fails and it is unable to maintain life activities, the organism dies. Therefore, most of the cancer cases admitted clinically are in progressive or advanced stages, while early stage cancer is relatively rare clinically because it does not affect the corresponding organs much and does not easily produce symptoms. Many advanced or progressive cancer cases are accompanied by extensive or distant metastases, or it is difficult to completely eradicate the cancer due to direct infiltration of adjacent organs, so the treatment process often involves the issue of palliative care. With the development of social economy and improvement of living standard, people’s demand for proper treatment of advanced tumor patients is gradually increasing, and many patients who gave up treatment or took negative treatment in the past hope to get active treatment; at the same time, the progress of medical technology has opened up many new ways for the treatment of advanced tumor, and many tumors that could not be treated in the past or the painful symptoms caused by tumor can be treated or controlled to some extent. Many previously untreatable tumors or painful symptoms caused by tumors can be treated or controlled to some extent. Therefore, palliative treatment for patients with advanced tumors deserves more and more attention. How to accurately evaluate the threat of different parts of the cancer to the organism according to various examination results, avoid the adverse effects of unreasonable treatment on patients, make palliative treatment more reasonable, and gradually move towards standardization has become an important task in clinical oncology work. Palliative care is a treatment method that can relieve the patient’s symptoms but not cure the underlying disease, as opposed to radical surgery. The former refers to the removal of most of the primary foci and metastases of the tumor, with cancer remaining in the naked eye; the latter does not remove the tumor at all, but only relieves the symptoms caused by the tumor. In fact, both radical surgery and palliative surgery refer to the subjective behavior of the surgeon, referring to the surgery itself. In clinical practice, it is found that even if radical surgery is performed with subjective efforts, it may not always achieve the effect of radical cure objectively, and in some advanced cases, cancer residue may still appear. In the diagnosis and treatment of gastric cancer, there are clear evaluation criteria for both the subjective act of radical gastric cancer surgery and the objective results obtained after the surgery, and the 11th edition of the Japanese Statute for the Treatment of Gastric Cancer classifies radical gastric cancer surgery into four categories, such as R0~3 (root 0~root 3), according to the scope of surgical removal, and also classifies the results of surgery into two categories, such as curative and non-curative, indicating whether there is still cancer residue after radical surgery. The objective results obtained by performing radical surgery for gastric cancer are evaluated in this way. With the improved understanding of the nature of cancer and the deeper understanding of cancer treatment, the 13th edition of the Statute for the Treatment of Gastric Cancer has changed the surgical modality from radical scope to four types of clearance scope: D0~3; and the surgical outcome from curative degree to radical degree: A, B and C, which refer to the scope of surgical resection exceeding (A) or equal to (B) or less than (C) the scope of cancer infiltration and metastasis, respectively. Although the C-level surgical outcome and palliative tumor resection in them are essentially the same, both referring to cancer residual after surgery, their meanings are slightly different. C-level surgical outcome refers to the objective result after performing removal surgery, while palliative tumor resection refers to the subjective behavior and process of surgical treatment, usually the surgical approach is planned and subjective behavior is performed in anticipation of cancer residual. Reasonable palliative surgery is to design C-level surgical outcomes that are conducive to patient survival and life. With the improvement of tumor diagnosis level, the clinical ability to grasp the infiltration and metastasis pattern of cancer and the harm caused to the organism is also improving, which makes it possible to design reasonable palliative surgery plan before surgery. Cancer has the characteristic of autonomous growth, which is out of the normal control of human body and grows and develops in the form of infiltration and metastasis without restriction. As a result, on the one hand, it continuously takes nutrients from the body and consumes the body indefinitely, making it gradually wasted and weakened; on the other hand, the infiltration and metastasis of cancer cause corresponding damage to the functions of the organs involved, and eventually the organs fail to function and the body dies. In fact, most of the cancer patients eventually die because of the failure of the organs involved by cancer. From this point of view, unlike cardiovascular and cerebrovascular diseases, the harm of cancer to human body is mostly indirect, affecting the function of corresponding organs through infiltration and metastasis first, and then threatening human life. Generally speaking, it takes a certain period of time from the appearance of cancer cells to the function of the affected organs, and there is still a period of time until the dysfunction of the corresponding organs appears, and then until their function fails and the organism eventually dies. Therefore, when the involvement of a certain organ is prominent and dysfunction occurs and endangers the life of a person first, a reasonable method to repair, replace or maintain the function of that organ can prolong the patient’s survival or improve the quality of life, which is palliative treatment. The radical treatment of cancer is to eliminate the direct and indirect effects of cancer on the body, while the palliative treatment is to win the survival time and quality of life for the patient by removing the deadliest threat of the cancer, which is the starting point of palliative treatment. Rational palliative surgery should begin with a comprehensive assessment of the primary and metastatic foci of cancer distributed throughout the body, identifying the major lesions that have the greatest impact on the function of vital organs and pose the greatest threat to life. Generally speaking, the main lesion is the primary lesion of the cancer, because the primary lesion has been growing for a long time and has the greatest impact on the function of the organ in which it is located. Metastatic foci usually appear later than the primary foci, and it takes some time for them to grow enough to affect the function of the corresponding organs and affect the organism later than the primary foci. However, sometimes metastases may become the main lesions that need to be treated first because of their more prominent effects on the body. For example: (1) metastases that grow too fast, such as liver-like adenocarcinoma of the stomach, are very likely to have liver metastases and grow rapidly in the liver, which may result in the development of liver metastases faster than the primary gastric cancer; (2) multiple metastases concentrated in a certain organ are likely to affect the function of that organ, and the more the number of metastases and the more concentrated they are, the greater the impact on the function of the corresponding organ, which may be life-threatening before the The greater the number and concentration of metastases, the greater the impact on the function of the corresponding organ, and it may be life-threatening before the primary focus. For example, if gastric cancer with multiple liver metastases has serious liver metastases and affects liver function, but the primary gastric cancer has neither acute bleeding nor obvious obstruction, then the metastatic liver cancer is the main lesion that threatens life the most; (3) metastases appearing in the key part of a certain organ will also directly affect the function of the organ and become the main lesion. For example, obstructive jaundice caused by gastric cancer with more serious lymph node metastasis around the common bile duct, as long as there is no complete obstruction or acute bleeding in gastric cancer, obstructive jaundice is the most prominent threat to life, and the treatment of gastric cancer should focus on resolving obstructive jaundice no matter what. After palliative treatment, the survival time and quality of life of patients depend on the impact of residual, untreated cancer on the function of important organs, so the evaluation of possible residual cancer is also very important. The assessment of residual cancer should include: ① the size and number of residual cancer, the more residual cancer, the larger the growth base and the faster the development, the faster the impact on the function of the corresponding organs, and the earlier the threat to the patient’s life. The higher the malignancy of cancer, the faster the residual cancer grows and the greater the threat to life. ③The law of metastasis and infiltration of cancer, in addition to the law of metastasis determined by the inherent biological characteristics of cancer, the influence of adhesions on the way of cancer progression after the initial surgery must be considered for cancer in the abdominal cavity, i.e., the increase of direct infiltration, the expansion of lymph node metastasis, and the decrease of peritoneal seeding. In cases where residual cancer is prone to metastasis to vital organs, attention should be paid in determining the therapeutic measures for the primary lesion. ④ The distance and anatomical relationship between residual cancer tumors and important organs are also very important factors. It should be said that the more distant the cancerous tissue is from the important organs, or from the critical parts of the important organs, the longer it takes to grow to the critical parts, and the later the effects on the functions of the corresponding organs appear. The anatomical connections between the two, such as ligaments and adhesive bands connecting the two, may become “bridges” for direct infiltration of cancer tissues, and residual cancer tissues may easily infiltrate directly into important organs through these structures and affect their functions. ⑤ Whether effective treatment or control methods are available for residual cancer tumors, the more definite the effect of subsequent treatment or control of residual lesions, the less threat it poses to the organism. Therefore, from the starting point of palliative surgery, it is prudent to perform palliative surgery when the possible residual cancer is large and of high malignancy, because after it relieves the most fatal threat to the organism from the cancer, the large base of multiplication and rapid growth of the residual cancer will soon lead to the emergence of the next fatal threat, and the surgery is not very meaningful. Rational palliative surgery must also take into full consideration the effects of surgical trauma on the residual cancer as well as the organism itself: ① After partial removal of the tumor, the residual cancer will grow faster, and this phenomenon is confirmed by animal experiments and clinical studies. Animal experiments show that the body will produce some substances that promote the proliferation of tumor cells, such as growth stimulating factors, after the primary tumor is removed; the primary tumor will also produce some substances that inhibit angiogenesis, such as angiostatin and endostatin, etc. After the primary tumor is removed, the residual cancer tissue and the metastatic tumor will have fewer factors that inhibit angiogenesis and supply vascularity is increased, which accelerates tumor growth. In addition, surgical trauma will have complex effects on the microenvironment of tumor growth and the anti-tumor immunity of the body, and also prompt the residual cancer tissue and metastatic cancer cells to shift from the dormant state to the proliferative state. ②Trauma will stimulate the accelerated growth of tumor. It should be said that the factors in the body that can promote tissue healing will also stimulate rapid tumor growth. Tumor-specific growth factor (TSGF) is one of the factors that have long attracted attention, and it can specifically promote tumor vascular proliferation and rapid tumor growth. Many studies have shown that as the degree of trauma increases, tumor-specific growth factor also increases significantly. Besides, there are growth factors and so on. ③The effects of surgical trauma on the organism and the potential threats such as complications of surgery increase with the expansion of trauma. ④Surgical trauma has a negative effect on the immunity of the organism. ⑤The patient’s postoperative quality of life is also greatly affected after extensive surrender of tissues and organs. Although surgery is necessary to relieve the lethal threat caused by cancer, the expansion of surgical trauma is not always proportional to the reduction of the body’s cancer load, and excessive surgical trauma may instead affect the patient’s quality of life in the limited survival time, or even threaten the patient’s survival and quality of life before the residual cancer. Therefore, it is also very important to appropriately control the degree of trauma of palliative surgery. For example, if advanced gastric sinus cancer directly infiltrating the pancreas is treated by pancreaticoduodenectomy, if there are quite serious metastases beyond the scope of surgical resection, such as with multiple liver metastases or with a certain degree of lymph node metastasis around the abdominal aorta, this operation should be performed with great caution because the patient is likely to have a long postoperative recovery period with difficulty in the limited survival time. Excessive expansion and increased surgical trauma do not provide much benefit to the patient. The starting point of palliative surgery for patients with advanced cancer is to relieve the most lethal threat to the organism from the cancer in order to win the time and quality of life before the arrival of the next lethal threat, the most lethal threat being the aforementioned major lesion and the next lethal threat being the residual cancer, and surgical trauma is both necessary to relieve the lethal threat and to stimulate the growth of the residual cancer and bring many negative effects. In radical surgery, it is only necessary to consider how to relieve the threat of cancer to the organism and the impact of surgical trauma on the organism, while in palliative surgery it is also necessary to consider the threat of residual cancer to the organism and the impact of surgical trauma on the residual cancer on top of that. Therefore, a reasonable palliative surgery should evaluate more accurately the benefit of surgical removal of part of the cancer to the patient, the impact of the possible residual cancer on the patient, and the impact of the proposed surgery on the residual cancer and the organism before the surgery is performed, and try to adjust the surgical trauma to the right level between the three, so as to remove the most fatal threat and delay the appearance of the next fatal threat, and also to ensure The aim of prolonging the survival time and improving the quality of life is to achieve the postoperative quality of life. Palliative tumor resection is suitable for cases where the main lesion is a more prominent threat to the organism, while the residual cancer will not affect the function of important organs temporarily and will not pose a threat to the organism. What can be removed must be the main part of the cancer, the part that threatens life the most; what remains must be the lesser part, the part that will not threaten life in the short term, never “put the cart before the horse” and cause harm to the patient. The smaller the threat of residual cancer to the organism, the more parts that can be effectively treated, the later the next fatal threat appears, the greater the significance of palliative treatment, and the closer the result is to radical surgery. At the same time, the less the threat of residual cancer to the organism, the more aggressive and thorough the treatment of the main lesion should be, with the aim of trying to make the next fatal threat come from the untreatable residual cancer rather than from the recurrence associated with the main lesion, etc. For example, in sigmoid colon cancer with obstruction as the main symptom and accompanied by lung metastasis, as long as the metastatic lung cancer does not affect respiratory function in the near future, the immediate life-threatening threat is the obstruction caused by sigmoid colon cancer, and the obstruction should be dealt with first. If sigmoid colon cancer cannot be resected, colostomy should be performed to relieve the direct threat of intestinal obstruction to patient’s life; if sigmoid colon cancer can be resected, metastatic lung cancer becomes the main lesion that threatens patient’s life afterwards, and the degree of treatment of sigmoid colon cancer still depends on the impact of metastatic lung cancer on the body: if metastatic lung cancer is relatively serious, it is not more meaningful to resect sigmoid colon cancer too thoroughly. As long as the main part of the primary focus is removed while the obstruction is lifted, so that the remaining part is less life-threatening than the metastatic lung cancer, too extensive resection will only increase surgical trauma and other disadvantages, which is not beneficial to the body; if the impact of the metastatic lung cancer on life is small, or if it is single and small in size, or if it is far from the bronchus, or if there is still a chance of re-operation, then the resection of sigmoid colon cancer should be more thorough. The purpose is to make the threat of possible recurrence after resection of sigmoid colon cancer lower than that of metastatic lung cancer, and then the palliative treatment carried out is more meaningful. If the main lesion cannot be resected, or if the preoperative evaluation of the cancer threatens the organism more, especially if the malignancy is higher and the residual cancer is more, even if the main lesion can be resected, it is not advisable to perform overly complicated surgical operations, otherwise, under the stimulation of trauma, the residual cancer will soon lead to the emergence of the next fatal threat and lose the meaning of treatment. Debulking operation is only suitable for removing part of the tumor to create conditions for subsequent treatment. If there is no effective follow-up treatment, it is very cautious to perform debulking operation alone. In this case, debulking operation is appropriate. Gastrojejunostomy for unresectable sinus cancer and lateral anastomosis of ileum and transverse colon for unresectable ascending colon cancer are often used in clinical practice. To obtain the most accurate and lasting effect with the simplest method and the smallest surgical trauma is the treatment principle of reduction surgery. With the development and progress of science and technology, there are many new techniques and instruments applied in the clinic, and satisfactory results have been achieved, making the complicated reduction surgery simpler and more in line with the interests of patients, and relieving many painful symptoms that could not be relieved in the past. For example, stent placement can relieve the obstructive symptoms of advanced esophageal cancer; PEG (endoscopic gastrostomy) and PEJ (endoscopic jejunostomy) can not only solve the nutritional support route for the obstruction of malignant tumors of head and neck, esophagus and stomach, but also lay the foundation for radiotherapy of tumors, and solve the problems such as difficulty in eating due to edema in the affected area during radiotherapy. Sometimes, simultaneous or sequential use of simple and reliable means to relieve the effect of cancer on the function of the corresponding organs one by one can enable the patient to survive longer. For example, in cases of unresectable gastric sinus cancer with lymph node metastasis around hepatoduodenal ligament and symptoms of both biliary obstruction and gastrointestinal obstruction, after PEJ is performed to relieve the gastrointestinal obstruction, a choledochal support can also be placed endoscopically to relieve the biliary obstruction, after which the patient’s survival time depends on the effect of gastric cancer on other organs or other symptoms of gastric cancer, such as bleeding and malignant mass. In cancers with low malignancy and low rate of progression, such methods can still prolong survival time, relieve patients’ pain and achieve the purpose of palliative treatment to a certain extent. Palliative surgery has something in common with controlled surgery in that both have the connotation of subjectively and appropriately controlling the scope of surgery. However, the starting point is different. Controlled surgery is performed because the body or one of its organs is overwhelmed by the negative effects of trauma or temporarily does not have the conditions for definitive surgery, and the intensity of the trauma is controlled in order to preserve the body and not to exceed the limits that the body can bear. The reason for this is the patient’s condition or the objective conditions of the time. In addition to the impact of trauma on the organism, the main reason for controlling the extent of resection in palliative surgery is to consider the impact of trauma on the residual cancer and the impact of the residual cancer on the organism. In some specific cases the two also intersect, such as those with important organ insufficiency or those who are old and frail and cannot tolerate larger radical surgery, according to the patient’s specific conditions, palliative surgery is chosen at the discretion of their organ function, and this kind of palliative surgery also belongs to controlled surgery. In summary, palliative treatment of tumor should be evaluated from three aspects in order to finally determine a more reasonable treatment plan. These are the benefit of removing the main lesion, the threat of the remaining cancer to the patient, and the impact of the treatment measures on the body and the residual cancer. Proper evaluation and reasonable measures are beneficial to the patient, while improper evaluation and unreasonable measures are likely to cause adverse effects on the patient and even accelerate the patient’s death.