Primary liver cancer (hereinafter referred to as liver cancer) is a common malignant tumor in China, and it is the 2nd in the mortality rate of malignant tumors. With the development of modern medical imaging, liver cancer can be correctly diagnosed in time. The effect of liver cancer treatment has also been greatly improved compared with before. The clinical application of various new technologies in recent years has provided more alternative treatment methods for liver cancer, but at the same time, it also faces the problem of how to reasonably apply various treatment methods and the comprehensive application of various methods, which is a research topic that should be paid attention to in the current treatment of liver cancer. Surgical resection of liver cancer Surgical resection is the traditional treatment method for liver cancer. Surgical resection with the aim of radical resection has been proven to prolong the survival of liver cancer patients, and is currently considered the only treatment method of choice that has the potential to completely cure liver cancer. Surgical resection is mainly used for liver cancer patients with limited lesions who are expected to be able to obtain radical resection. Since most of the patients with liver cancer in China are combined with cirrhosis, extended lobectomy is mainly used for a few patients with insignificant cirrhosis, and local resection is the main resection method. However, recurrence after resection is the main obstacle limiting the long-term survival of patients, and the recurrence rate can reach 30.1%, 62.3% and 79.0% at 1, 3 and 5 years after resection, respectively, thus adjuvant therapy after resection to prolong the postoperative survival of patients has become an important topic of current research. Unfortunately, however, the results of clinical trials have shown that there are limited measures to definitely reduce postoperative recurrence rates or prolong survival. Clinical trials have shown that postoperative adjuvant arterial chemoembolization (TACE) does not prolong survival in patients undergoing radical surgical resection; however, in patients with vascular invasion, multiple nodes, or large hepatocellular carcinoma, TACE can help prolong survival. Other adjuvant therapies including postoperative application of interferon or lymphokine-activated killer cells can also reduce postoperative recurrence and prolong survival, but they are expensive and should be applied appropriately according to economic conditions. After more than 30 years of clinical application, it has been confirmed that TACE can prolong the survival rate of patients for 3 years. For patients with hepatocellular carcinoma with decompensated liver function (e.g. Child C), TACE should be used with caution, as it may cause more damage to liver function than the benefit of treating the tumor. In order to achieve long-term survival, other local treatments such as intratumoral anhydrous alcohol injection, radiofrequency destructive therapy, microwave coagulation, etc. can be combined. For cases with shrinking tumor and limited lesions, surgical resection can be performed without losing time to obtain long-term survival. Intratumoral percutaneous ethanolinjection (PEI) The protein coagulation effect of anhydrous alcohol and microvascular embolization are the mechanisms of its treatment for hepatocellular carcinoma. After more than 20 years of clinical application, it has been proved that the long-term effect of selective application in the treatment of hepatocellular carcinoma is similar to that of surgical resection, but PEI is mainly applied to cases with diameter less than 3 cm and the number of nodules within 3; patients with severe liver function loss or obvious coagulation dysfunction are not suitable. In order to achieve complete tumor necrosis, multiple injections at multiple points are often required. The effect of PEI can be improved if it can be combined with TACE, which causes ischemic necrosis of the tumor and destroys the fibrous septum inside the tumor, which is conducive to the diffusion of anhydrous alcohol and reduces the residual tumor after treatment. Radiofrequency ablation (RFA) is a widely used local treatment for hepatocellular carcinoma in recent years, which utilizes the thermal destruction effect of radiofrequency electrodes and the embolization effect of microvessels to achieve complete destruction of local tumor. The 5-year survival rate for small hepatocellular carcinoma can reach 33% ElO J. Currently, the commonly used RF electrodes are 3.5 cm in diameter, and there are also RF electrodes of 4.0 cm or even 5.0 cm. For tumors larger than 4.0 cm, it is difficult to ensure complete destruction even with multiple treatments. Therefore, RFA is mainly suitable for small hepatocellular carcinoma less than 4.0 cm in diameter, especially for small hepatocellular carcinoma with severe cirrhosis that cannot be removed surgically. For tumors larger than 4.0 cm in diameter, if combined with TACE chemotherapy, the destruction area can be expanded to achieve complete destruction of the tumor [11j. For tumors near large blood vessels, subcellular membrane or near gallbladder, it is difficult to achieve complete destruction after RFA treatment, and the in situ recurrence rate is high, so it can be combined with tumor PEI to destroy the blind area of RFA treatment to achieve complete destruction. Although RFA can achieve better long-term survival, even similar to surgical resection, the higher recurrence rate of local or residual liver after surgery is valued, and the factors associated with recurrence are tumor diameter greater than 3 cm, tumor proximity to the envelope or tumor proximity to large blood vessels. How to apply local or systemic adjuvant therapy to reduce the recurrence rate after RFA will be an important research topic. Systemic chemotherapy for hepatocellular carcinoma is the traditional treatment for hepatocellular carcinoma. However, since liver cancer is not a tumor sensitive to chemotherapy, the effect of systemic chemotherapy is poor, and there are almost no reproducible chemotherapeutic drugs or chemotherapy regimens that can reach 20% or more, whether applied as individual chemotherapeutic drugs or in combination. In recent years, combination chemotherapy regimens including interferon have been used to treat hepatocellular carcinoma, and their efficacy appears to have improved. For example, continuous intravenous infusion of 5-fluorouracil (5-FU) 200 mg•m~•d ×21 d for 28 d as a cycle, combined with subcutaneous interferon ct-2b (4 MU/m, 3 times weekly), resulted in objective remission in 25% of patients with hepatocellular carcinoma and 62.5% of patients with fibrous lamellar hepatocellular carcinoma. Another clinical trial showed that 5-FU (250 mg•m~•d~ for 5 d), cisplatin (10 mg•m~ •d~ for 5 d), and only one interferon (2.5 MU, 3 times a week) treated 6 cases of inoperable hepatocellular carcinoma with partial remission in 2 cases¨cited. However, overall, the effect of systemic chemotherapy for hepatocellular carcinoma is still not groundbreaking and still not the main treatment for hepatocellular carcinoma. VI. Radiation therapy Because the liver is a radiation-sensitive organ, especially the liver damage after radiation therapy is a late reaction, which often occurs among the months after the end of radiation therapy, coupled with the fact that most liver cancer patients are combined with cirrhosis, liver damage after radiation therapy for liver cancer hinders the application of radiation therapy in liver cancer treatment. However, with the accumulation of experience in radiation therapy for liver cancer and the rational application of radiation dose, coupled with the clinical application of 3D conformal radiotherapy, the effect of radiation therapy for liver cancer has been significantly improved compared with that in the past. Especially as one of the comprehensive treatment means for liver cancer, it is of great significance to improve the effect of comprehensive treatment for liver cancer and prolong the survival of patients. For patients with metastasis of hilar lymph nodes or abdominal lymph nodes, or portal vein thrombosis, it can be used as palliative treatment to help relieve symptoms and prolong survival. Biological therapy Biological therapy was once considered as the fourth treatment mode after surgical resection, chemotherapy and radiotherapy, and is a promising treatment method. However, the biological agents currently applied in the treatment of liver cancer have failed to show significant therapeutic effects. However, being one of the integrated treatment methods, it has been valued in reducing the recurrence rate of hepatocellular carcinoma after resection. For example, Q-Interferon and autologous lymphokine-activated killer cells (LAK) have been applied to reduce the recurrence rate of hepatocellular carcinoma after resection. Recently, it has also been reported that the application of formalin-fixed autologous tumor vaccine to patients after hepatectomy significantly reduced the postoperative recurrence rate, suggesting that biological therapy will have an important role in preventing recurrence. In conclusion, the selection of various therapeutic methods should be aimed at obtaining the best therapeutic effect and the principle of strictly mastering the indications of various therapeutic methods. The treatment of hepatocellular carcinoma involves multiple disciplines such as surgery, internal medicine, radiation and chemotherapy, each of which has its own strengths and weaknesses, and the best therapeutic effect should be obtained through the organic collaboration of multiple disciplines.