Primary liver cancer is one of the malignant tumors that seriously threaten people’s health in China, and China is a high incidence area for liver cancer. In recent years, the incidence rate of liver cancer in China is still on the rise, and the age-specific incidence rate of liver cancer reaches 31.7 per 100,000 people per year. In 1995, according to the Ministry of Health, the number of liver cancer deaths in China in the early 1990s was 20.40 per 100,000 people per year, ranking second in the mortality rate of malignant tumors. It is second only to lung cancer in urban areas and second to stomach cancer in rural areas. Liver cancer can be seen in all age groups, and the higher the mortality rate of liver cancer, the lower the age of incidence. In high incidence areas, the ratio of male to female incidence is 3-4:1, while in low incidence areas, it is 1-2:1. Liver cancer is also a tumor with high malignancy and poor prognosis, and more than 94% of patients eventually die from this disease. Lee et al. reported that the average survival of untreated patients with diagnosed progressive hepatocellular carcinoma was 1-4 months. In France, Borie et al. reported that the overall 5-year survival rate of 1007 patients with hepatocellular carcinoma did not exceed 9%, with a surgical resection rate of 10%-31% and a 5-year postoperative survival rate of 29%-39%. In Western countries, the number of patients with hepatitis B infection or combined cirrhosis is less, and the 5-year survival rate after surgical resection is 27-49%; in Eastern countries, patients with combined post-hepatitis cirrhosis have a lower 5-year survival rate after surgical resection than in Western countries, with 10.7%-39% reported by different scholars. Therefore, we know that liver cancer is a malignant tumor that seriously endangers health and life. However, strictly speaking, there is no treatment method that can cure all kinds of liver tumors with absolute certainty. There are many methods to treat liver cancer, including liver transplantation, liver resection, ablation, hepatic artery embolization chemotherapy (TACE), targeted therapy (sorafenib), systemic chemotherapy and supportive therapy. However, different methods have corresponding indications, i.e. different stages of liver cancer should be treated in different ways. Therefore an appropriate liver cancer staging becomes very important. The purpose of cancer staging is to establish a disease prognosis system and to provide appropriate treatment for the best candidate cases. There are many kinds of liver cancer staging commonly used in clinical practice: Barcelona staging (BCLC), Okuda staging in Japan, TNM staging by the American Joint Committee on Cancer (AJCC), CLIP staging by the Italian Cancer Program, etc. However, BCLC staging has become the standard staging system for clinical treatment of liver cancer. The correctness of this staging system has been externally confirmed15 and has been recognized by the American Association for the Study of Liver Diseases (AASLD) and the European Society of Liver Diseases (EASL). This system links tumor staging to treatment strategies. Barcelona staging divides hepatocellular carcinoma into 5 stages: very early (single, tumor diameter less than 2 cm, no vascular invasion, normal liver function), early (single tumor without vascular invasion or number of tumors less than 3, diameter less than 3 cm, normal liver function), intermediate (multinodular asymptomatic tumor without invasive features), advanced (symptomatic tumor or EOCG score 1-2 or vascular infiltration/extrahepatic metastases) and end-stage (ECOG score 3-4, Child-pugh grade C). Radical options for liver cancer include liver transplantation, surgical resection of liver cancer and ablation. However, only very early, early and some intermediate stage patients can be treated radically. Most intermediate stage patients are recommended to undergo hepatic artery embolization chemotherapy, advanced stage patients can consider targeted therapy, and end-stage patients are recommended to be treated symptomatically. Surgery is the main treatment for hepatocellular carcinoma. If suitable patients are strictly selected before surgery, then resection and liver transplantation can achieve the best results with 5-year survival rate of 60-75%, which becomes the first choice of treatment for patients with early-stage tumors. In recent years in China, due to the importance of early detection and treatment of early-stage liver cancer and very early-stage liver cancer, the surgical treatment effect of primary liver cancer has also been significantly improved in some large liver cancer treatment centers. Wu Mengchao et al. summarized the surgical treatment of 5524 cases of primary liver cancer and found that the five-year survival rate after liver cancer surgery could be as high as 48.6% due to the emphasis on early diagnosis of small liver cancer and subclinical liver cancer; Yang Binghui [19] reported that the five-year survival rate after surgical resection of early liver cancer patients was as high as 59.1% in 3250 patients. In addition, Tang Zhaoyou [20] reported a 10-year survival rate of 29.2%. However, patients who can undergo liver resection only account for about 30% of all hepatocellular carcinoma patients, and the majority of other patients do not have the opportunity to undergo surgery, mainly because the reserve function of the liver is too poor, the tumor has invaded major blood vessels and cannot be resected or the location is difficult to resect. Currently, many centers use the combination of Child-pugh classification and 15-minute indole indocyanine green storage rate (ICG15) to determine the reserve of liver function. Hepatectomy for cirrhotic patients requires careful patient selection, i.e., detailed knowledge of the patient’s tumor stage, risk factors associated with postoperative morbidity and mortality, tumor recurrence and survival time, as well as ensuring skilled surgical technique. The selection of surgical patients is now very well defined, and the development of surgical techniques such as ultrasonic knife, waterjet, intraoperative ultrasound, Pringle method, and postoperative management have been optimized. In addition, techniques such as anatomic hepatectomy proposed by?Couinnaud et al. and anterior approach hepatectomy proposed by Fan ST et al. have led to a partial solution to the problem of intrahepatic tumor recurrence after resection. Until the 1990s, hepatic resection was recognized as the best treatment for hepatocellular carcinoma and the hope for its eradication. In fact, hepatectomy + regional chemotherapy did achieve good results. The average 5-year survival rate of small hepatocellular carcinoma is close to 50%. In recent years, the introduction of some new treatment methods, such as microwave curing, radiofrequency ablation, high-energy focused ultrasound, radiofocused knife, alcohol injection, radioactive particle implantation, cryotherapy, etc., has brought new hope for those liver cancer patients who cannot undergo resection surgery. These methods are less invasive, simple to operate and less risky, so they are not a bad choice. Especially, radiofrequency ablation is playing an increasing role in the treatment of unresectable small hepatocellular carcinoma, small hepatocellular carcinoma recurring after tumor resection and hepatocellular carcinoma patients waiting for liver transplantation. In the initial treatment of small hepatocellular carcinoma, radiofrequency ablation has achieved results similar to those of surgical resection. Since the lesion of soil cirrhosis, where hepatocellular carcinoma occurs, has not been completely eradicated, the tumor recurrence rate is high and its long-term outcome remains to be further observed. The rise of liver transplantation technology has revolutionized the concept of liver surgery. Liver transplantation not only removes the tumor, but more importantly, removes the entire diseased liver at the same time, eliminating the “soil-cirrhotic liver” where liver cancer occurs, and the transplanted new liver relieves the worry of liver reserve insufficiency. The transplanted new liver relieves the worry of inoperable liver reserve. It also gives patients with liver cancer who are inoperable due to liver dysfunction a chance for radical cure. Liver transplantation for cirrhosis combined with small hepatocellular carcinoma has achieved satisfactory results and has been unanimously recognized by domestic and international experts, with a 5-year survival rate of 80% after surgery. According to the data shown in the Chinese liver transplantation registry, the 5-year survival rate of liver transplantation for cirrhosis combined with small liver cancer in China has also reached about 70%, which is significantly higher than that of the surgical resection group [34]. Wu Mengchao [18] summarized the surgical treatment of 5524 cases of primary liver cancer in his single center and found that the surgical treatment of liver cancer had made great progress by the end of last century, and the 5-year survival rate after surgery increased from 20% to 50%, but the 5-year survival rate after surgical resection has not been further improved in the last decade because the original surgical resection method could not reduce the recurrence rate of the tumor and could not eliminate the “soil” in which liver cancer occurred. -Sclerotic liver”. Studies have shown that the atypical proliferation of hepatocytes in the sclerotic liver is diffuse and the growth of hepatocellular carcinoma is multicentric. At the same time, due to the existence of portal hypertension and poor reserve function of the sclerotic liver, the scope of liver resection is significantly limited, so partial hepatectomy is often ineffective in completely removing the tumor. Liver transplantation has come a long way in the treatment of liver cancer. In theory, liver transplantation not only removes all of the liver tumor and potential multicentric subfoci, but also removes the diseased liver and prevents the recurrence of liver cancer. However, early liver transplantation was almost always used for patients with advanced liver cancer, and the overall outcome of liver transplantation for liver cancer was discouraging, with a 5-year survival rate of less than 20%, making liver cancer a relative contraindication to liver transplantation from its initial use as the main indication for liver transplantation. Since the 1990s, the proportion of liver cancer recipients in some transplantation centers in Europe and the United States has increased, mainly due to advances in liver cancer tumor biology and improved liver transplantation efficacy. The results of studies in liver transplantation centers worldwide are relatively consistent in affirming the good efficacy of liver transplantation for early-stage liver cancer, and liver transplantation for liver cancer brings us a bright prospect in theory and practice. The key question now is how to define early stage liver cancer. In 1996, Mazzaferro et al [24] recommended the Milan criteria: a single tumor ≤ 5 cm in diameter or less than three multiple tumors with a maximum diameter ≤ 3 cm, No large vessel infiltration, no lymph node or extrahepatic metastasis. The advantages of this criterion are that the efficacy is certain, the 5-year survival rate is above 75%, the recurrence rate is less than 10%, and only the size and number of tumors need to be considered, which is convenient for clinical operation. Therefore, Yao et al [25] from the University of California, San Francisco (UCSF) proposed new criteria: (i) the diameter of a single tumor should not exceed 6.5 cm, or the number of tumors should not exceed 3, the maximum diameter should not exceed 4.5 cm, and the total tumor diameter should not exceed 8 cm; (ii) there is no vascular or lymph node invasion. Duffy [26] et al. recently found no statistically significant difference in 5-year survival rates between those meeting the Milan criteria and those meeting the UCSF criteria in a follow-up of 467 liver transplant patients with liver cancer at the UCLA Liver Transplant Center from 1984 to 2006. Recently, Mazzaferro43 and others proposed new up-to-7 criteria for liver transplantation for hepatocellular carcinoma, suggesting that patients with hepatocellular carcinoma with a maximum tumor diameter of less than 7 cm, a maximum number of up to 7, and no vascular invasion could have a 5-year survival rate of 71.2% after transplantation. However, the currently accepted criteria for liver transplantation for hepatocellular carcinoma do not take into account the biological characteristics of the tumor, such as vascular invasion, lymphatic metastasis, tumor grade and tumor markers. Recently, Toso et al. reviewed and analyzed the prognosis of 6478 adult liver transplant patients with liver cancer and found that preoperative tumor volume and methemoglobin level were the most important factors affecting prognosis. However, in practice, such as the Japanese Kyoto criteria are to be relaxed a bit, and similarly achieved better results. Combining with our situation, we believe that no extrahepatic metastasis, no cancer thrombosis and no invasion of large blood vessels are the bottom line of liver transplantation for hepatocellular carcinoma. The preoperative treatment, surgical operation, intraoperative prevention, rational application of immunosuppressants, and postoperative chemotherapy also have an important impact on the prognosis of liver transplantation for hepatocellular carcinoma. Liver transplantation may be the best treatment option for liver cancer patients, but the shortage of donors prevents many patients from getting timely treatment. Therefore, pre-transplantation treatment is also very important. It has been reported in the literature that liver tumor resection before transplantation does not affect survival after transplantation. Pre-transplantation treatment also includes hepatic artery embolization chemotherapy, radiofrequency ablation, etc., which also achieved good results. 80% of patients with recurrent hepatocellular carcinoma after resection were reported to have a chance of liver transplantation by Poon et al. Of course, it has also been reported that patients who underwent liver transplantation after liver tumor resection had a significantly higher perioperative mortality rate than those who underwent liver transplantation without a history of resection. Adequate preoperative preparation, operator familiarity with anatomy, and meticulous manipulation prior to liver transplantation in patients with a history of abdominal surgery may be a safeguard to reduce perioperative mortality. For patients with diffuse hepatocellular carcinoma or existing cancer thrombus in the portal vein branches, catheter embolization chemotherapy or the choice of the molecularly targeted drug sorafenib may be considered if liver function is good. The efficacy of TACE has been affirmed by scholars both at home and abroad. In the 1990s, this was confirmed by many larger clinical trials. For example, Bronowicki et al [36] reported a 4-year survival rate of 27% after TACE treatment in 127 cases of hepatocellular carcinoma. While patients with poor liver function can only choose supportive therapy or immunotherapy. lo44 et al. reported a good effect with interferon after hepatectomy for hepatocellular carcinoma. Systemic chemotherapy, as an important tool in the comprehensive treatment of hepatocellular carcinoma, still needs attention in the treatment of hepatocellular carcinoma. However, chemotherapy for hepatocellular carcinoma is not mature at present. The low efficacy and high side effects of traditional systemic chemotherapy have kept the role of chemotherapy in the treatment of liver cancer in question. Most chemotherapeutic drugs have been tried in the treatment of liver cancer, but their effectiveness is very little, with single-drug efficiency <10% and 1-year survival rate of chemotherapy alone only 2-5.4%. At present, surgical resection is still the main means to improve the survival rate of primary hepatocellular carcinoma, but about 80% of patients have severe hepatic insufficiency, intrahepatic dissemination or distant metastasis at the time of hepatocellular carcinoma surgery, and the surgical resection rate is low or the recurrence rate after surgery is high, so comprehensive treatment of hepatocellular carcinoma has been the accepted treatment mode.