Primary liver cancer (PLC) is one of the common malignant tumors in China. Every year, about 140,000 people die of liver cancer in China, accounting for about 50% of the deaths from liver cancer worldwide. Since liver cancer is insidious in origin and has no symptoms in early stage, and most patients lack awareness of screening, they often go to hospital only when symptoms appear and are diagnosed as advanced liver cancer, and the survival period of advanced liver cancer is usually only 3-6 months. Because of this, liver cancer was once called the “king of cancers”. After decades of efforts, the treatment level of liver cancer has been greatly improved, and the 5-year survival rate of patients with liver cancer removed by surgery has been significantly increased, up to 85%. To improve the survival rate of liver cancer patients, standardized diagnosis and treatment are indispensable. Regarding the standardized diagnosis and treatment of liver cancer, some international organizations and associations are updated regularly, including: American Association for the Study of Liver Diseases (AASID), National Comprehensive Cancer Network (C-CN), Asia-Pacific Association for the Study of the Liver (APASI), British Society of Gastroenterology (BSG), American College of Surgeons (ACS), Barcelona Liver Cancer Collaborative Group (BCLC). (BCLC). In recent years, organizations such as the Liver Cancer Committee of the Chinese Anti-Cancer Association have published the Standardized Treatment of Liver Cancer 2008 Edition, the Standardized Treatment of Liver Cancer 2009 Edition, and the Expert Consensus on Standardized Diagnosis and Treatment of Primary Liver Cancer, and recently published the Standardized Treatment of Liver Cancer 2011 Edition. Faced with so many guidelines, norms and consensus, many physicians are at a loss, and it is not easy to read through them once, let alone understand, use them well and apply them. In this article, we briefly discuss our understanding of hepatocellular carcinoma diagnosis and treatment based on the study of relevant diagnosis and treatment standards and the author’s clinical experience, for the reference of liver surgeons. Since more than 90% of primary liver cancer is hepatocellular carcinoma (HCC), this article refers to HCC in particular. Early diagnosis is the key to improve the efficacy of hepatocellular carcinoma. Early diagnosis of liver cancer is not difficult, but the key is to popularize the knowledge of early diagnosis and make people, especially those at high risk of liver cancer, aware of census. The high-risk groups of liver cancer include men over 40 years old or women over 50 years old, those with HBV (and) HCV infection, alcoholism, combined diabetes and family history of liver cancer. Early diagnosis of hepatocellular carcinoma is made by checking serum alpha-fetoprotein (AFP) and liver ultrasound every six months. It is important to emphasize here that once every six months is not the normal annual checkup, because liver cancer develops from cancer to middle to late stage in about 10 months, so once a year will miss the opportunity to detect early liver cancer. 2. The diagnosis of liver cancer is not difficult, but it is difficult to choose the appropriate diagnosis method. Pathological diagnosis is still the gold standard for liver cancer diagnosis, but the clinical diagnosis of liver cancer has been widely recognized in China and abroad. The clinical diagnosis of hepatocellular carcinoma depends on three main factors, namely, the background of chronic liver disease, imaging findings and serum AFP level. The clinical diagnosis of HCC can be established when two of the following conditions are met: (i) evidence of cirrhosis and HBV (and/or HCV) infection [HBV (and/or HCV antigen positive]; (ii) typical imaging features of HCC: simultaneous multi-row CT scan and/or dynamic contrast-enhanced MRI showing rapid inhomogeneous vascular enhancement of the hepatic occlusion in the arterial phase, and venous or venous phase. a. HCC can be diagnosed if the liver occupancy is ≥2 cm in diameter and one of the two imaging examinations, CT and MRI, shows that the liver occupancy has the features of hepatocellular carcinoma mentioned above; b. If the liver occupancy is 1-2 cm in diameter, both CT and MRI imaging examinations are needed to show that the liver occupancy has the features of hepatocellular carcinoma mentioned above in order to diagnose HCC. HCC to enhance the specificity of diagnosis; ③ serum AFP ≥ 400ng/L for 1 month or ≥ 200ng/L for 2 months, and other causes of elevated AFP can be excluded, such as pregnancy, germline embryonic-derived tumors, active liver disease and secondary liver cancer. Diagnostic methods of hepatocellular carcinoma include B ultrasound, CT, MRI, PET-CT, hepatic arteriography and biopsy. Firstly, B ultrasound is the most commonly used examination, which is simple, non-invasive, inexpensive and repeatable at any time, but ultrasound examination requires the highest level of skill and experience. Ultrasound can also guide the puncture needle during local treatment such as radiofrequency microwave. Ultrasound is very convenient for identifying fluid or substantial occupations; color multispectral and ultrasonography can dynamically observe the blood flow of lesions and help to identify benign and malignant tumors in the liver. Secondly, CT is one of the most important imaging examinations for the diagnosis of liver cancer. Enhanced CT is necessary for the diagnosis of liver cancer, including four periods: plain phase, arterial phase, portal phase and delayed phase. The typical presentation of hepatocellular carcinoma is significant enhancement in the arterial phase (vash-in) and persistent fading of contrast in the venous/delayed phase (vash-out). Magnetic resonance imaging (MRI) is also generally required for enhancement. The advantages of MRI are no radioactive radiation, high tissue resolution, multi-directional and multi-sequence imaging, and better display and resolution than CT and US for structural changes inside the liver cancer lesion such as hemorrhagic necrosis, steatosis and double envelope. It is difficult to say which one is better, but it is best to combine the two for a comprehensive evaluation. The degree of mastery and familiarity varies from hospital to hospital and from physician to physician, which can have an impact on the quality of the examination and the accuracy of the diagnosis. In recent years, the advantages of PET-CT in preoperative diagnosis of malignant tumors and postoperative evaluation of recurrence and metastasis have been increasingly recognized by physicians, and its advantages include both morphological and functional imaging, which can understand the size and metabolic changes of tumors before and after treatment, and whether there are distant metastases. Therefore, it is not used as a routine test for the diagnosis of liver cancer, but is often used for the evaluation before liver transplantation to exclude distant metastases. So far, hepatic arteriography is the most sensitive imaging test for hepatocellular carcinoma. Intraoperative injection of iodinated oil and CT scan (iodine-free CT) 3-4 weeks later can detect microscopic lesions (8-9 mm) that cannot be shown by CT or MRI, except for a very small number of oligohematoma. It should be pointed out that less than 10% of liver cancers have true oligoblood supply in clinical practice, and the “oligoblood supply” shown by B ultrasound, CT and MRI may not necessarily be true oligoblood supply, but it may be that the tumor is in a part of the body where blood flow is difficult to be measured by ultrasound, or the contrast dose and speed of CT or MRI enhancement may not be sufficient to show the blood supply. It may also be due to insufficient contrast dose and speed during CT or MRI enhancement. Therefore, hepatic arteriography can still be used for hepatocellular carcinoma with “less blood supply” shown by B ultrasound, CT or MRI. Hepatic arteriography can be performed simultaneously with chemoembolization of the lesion (commonly known as interventional therapy), so it can be said that interventional therapy is not only a treatment for liver cancer, but also a good diagnostic method. Hepatic arteriography is an invasive test, but it is safe and can be used for patients whose diagnosis cannot be confirmed after other tests. In addition, even for hepatocellular carcinoma that presents as limited resectable on imaging, preoperative hepatic arteriography has been advocated to clarify the presence of other multiple small lesions. Liver aspiration biopsy can obtain the pathological diagnosis of hepatocellular carcinoma as well as understanding molecular markers and other conditions, which are very important for clarifying the diagnosis, pathological type, guiding treatment and judging prognosis. Liver aspiration biopsy is generally safe, and the incidence of needle tract implantation is about 3.4%. However, due to the international recognition of clinical diagnosis of liver cancer and the fact that liver aspiration biopsy has certain risks (such as abdominal or biliary bleeding and needle tract metastasis) and is not recommended by liver surgeons, it is not commonly used in clinical practice. 3.There are many treatment methods for liver cancer, and the key is reasonable selection and joint application. Treatment methods of hepatocellular carcinoma include: surgical resection, liver transplantation; local treatment includes radiofrequency, intratumoral alcohol injection, microwave, freezing, hepatic artery interventional chemoembolization, high-powered ultrasound focused ultrasound knife; radiotherapy includes conformal radiotherapy, intensity modulated radiotherapy, γ-knife, radio-wave knife, spiral tomotherapy system, etc.; systemic treatment includes chemotherapy, immunotherapy, anti-angiogenic therapy, targeted therapy, Chinese medicine; for underlying diseases (such as cirrhosis and hepatitis) and various complications treatment. To reasonably select various treatment methods, generally speaking, the following principles should be followed and considered: (1) the basic principles of safety, economy and effectiveness, which are also the highest principles of treatment for all diseases. ②Treatment of hepatocellular carcinoma should consider 4 factors: number, size, location, whether there is vascular invasion, lymph node metastasis or distant metastasis; liver function; patient’s general condition and antiviral treatment. (3) Surgical resection is still the first choice of liver cancer treatment. Anything that can be surgically resected, especially those that can achieve radical resection, should be resected as much as possible. Palliative resection does not necessarily bring benefits to survival. ④Interventional therapy is the most widely used treatment for liver cancer and can be said to be the basic treatment for liver cancer. ⑤ Pay attention to antiviral therapy, viral hepatitis is the underlying disease of liver cancer, and literature reports that nucleoside antivirals (lamivudine) can reduce the occurrence of liver cancer for those with hepatitis B cirrhosis, while combined antiviral therapy for liver cancer patients has the potential to reduce post-treatment recurrence and prolong survival. (6) Comprehensive treatment is always the best option for hepatocellular carcinoma treatment, and the combined application of several therapies is more effective than single treatment. There is no unified model of comprehensive treatment plan, which is worth exploring. The choice of comprehensive treatment plan depends on the physician’s experience, disease condition and patient’s economic condition. The following is a brief description of each treatment. (1) Surgery The prerequisite for surgery is liver function and general condition: ①Tumor size is not strictly limited, generally speaking, it is better to be under 10cm in diameter, because tumors >10cm in diameter are often combined with multiple satellite foci or vascular invasion, and surgery is often incomplete. The number of tumors should not exceed 2, sometimes it can be relaxed to 3. If the number of tumors is 4 or more, surgery is usually not suitable. Because more than 4 lesions often suggest the presence of other multiple small lesions, hepatic arteriography and intervention are strongly recommended in this case. Even if resection is reluctant, it is mostly palliative and the prognosis is poor. ③Vascular invasion, lymph node metastasis or distant metastasis are generally not suitable for surgery, and such surgery is mostly palliative, although some patients do benefit from palliative surgery. ④Laparoscopic hepatectomy: the scope of application is not wide, and it is suitable for tumor location is more superficial and near the liver margin, usually II~VI liver segment. It has the advantages of less trauma, less blood loss and faster recovery. (2) Transplantation: ① Milan standard (single tumor diameter ≤ 5cm or less than 3 and maximum diameter ≤ 3cm) of HCC patients, is a more strict standard in liver transplantation, which is widely adopted internationally. The advantages are that the efficacy is certain, the 5-year survival rate is ≥75%, the recurrence rate is <10%, and only the size and number of tumors need to be considered, which is convenient for clinical operation. The disadvantages are: the Milan criteria are too strict, and some patients who can benefit from liver transplantation are rejected; there is no significant difference in the overall survival rate between liver transplantation and liver resection for small hepatocellular carcinoma meeting the Milan criteria, except that the tumor-free survival rate of the former is significantly higher than that of the latter. ②There are other criteria based on the Milan criteria. The University of California, San Francisco (UCSF) criteria include single tumor diameter not exceeding 6.5 cm, multiple tumors ≤3, maximum diameter ≤4.5 cm, total tumor diameter ≤8 cm, and no vascular or lymph node invasion; the Pittsburgh modified TNM criteria include only the presence of any one of the three criteria: large vascular invasion, lymph node involvement, or distant metastasis. (Pittsburgh's modified TNM criteria only include the presence of any one of the three criteria: large vessel invasion, lymph node involvement or distant metastasis as a contraindication to liver transplantation, but not the size, number and distribution of tumors as criteria for exclusion.) ③Many domestic institutions and scholars have put forward different criteria, including Hangzhou criteria, Shanghai Fudan criteria, Huaxi criteria and Sanya consensus, etc. ④The 2011 edition of China's liver cancer diagnosis and treatment guidelines tend to recommend the UCSF criteria. ⑤ The requirements for tumor size and number vary among the standards; however, the requirements for the absence of large vessel invasion, lymph node metastasis and extrahepatic metastasis are consistent. (6) The prevention of recurrence should still be emphasized after liver transplantation, and appropriate drug therapy (including antiviral therapy as well as chemotherapy, etc.) can be administered to reduce and delay the recurrence of liver cancer, but there is a lack of sufficient evidence-based medical evidence. (3) Local treatment (radiofrequency, microwave, freezing, alcohol injection): ①The common feature of these local treatments is to insert radiofrequency, microwave or freezing needles directly from the body surface through ultrasound and other imaging tools, using temperature or alcohol to destroy tumor cells; ②Their more strict indications are the same, namely: the number of tumors ≤3; the diameter does not exceed 3 cm; of course, they are also used for slightly larger tumors, but there is also the risk of incomplete treatment; ③The risk of incomplete treatment. There is a risk of incomplete treatment; (3) these treatments have some restrictions on the location of the tumor, preferably the tumor is located in the deep part of the liver. Tumors adjacent to peripheral areas such as diaphragmatic surface, gastrointestinal area, gallbladder and hepatoportal are prone to peripheral organ damage and induce complications of hepatocellular carcinoma rupture; invasion of adjacent large blood vessels or tumor rich blood supply causes heat loss ("heat sink effect"), resulting in tumors prone to residual recurrence; also not applicable to hepatocellular carcinoma located in image blind area. (4) Intervention: (1) Applicable to multiple tumors (4 or more), with cancer emboli, satellite foci, incomplete envelope, or AFP not turned negative 2 months after surgery; (2) Many liver tumor physicians think that interventional therapy is harmful to liver function, but because the blood flow of liver tumor is greater than that of normal liver tissue, by reducing the amount of chemotherapy, slowly injecting iodine oil and other measures, it can almost avoid injecting drugs into normal liver tissue, and make most drugs enter into the tumor. However, because the blood flow of liver tumor is greater than that of normal liver tissue, by reducing the amount of chemotherapy and slowly injecting iodine oil, it can almost avoid injecting drugs into normal liver tissue and make most of the drugs enter into the tumor. As long as the patient's systemic condition permits, the tumor is not in the final stage, and the expected survival time is more than 6 months, interventional therapy can be considered. One patient with hepatocellular carcinoma has survived for 12 years after surgical resection combined with interventional therapy and antiviral treatment by the author. (5) Radiation therapy: ① Radiotherapy is often used when the tumor is confined and cannot be removed surgically due to poor liver function, or when the tumor is located in important anatomical structures and cannot be removed technically, or when the patient refuses surgery. In addition, palliative treatment is sometimes feasible for patients who have distant metastases to control pain or relieve compression, etc. Radiotherapy includes 3D conformal radiotherapy, intensity modulated conformal radiotherapy and stereotactic radiotherapy. ③Newer radiotherapy devices include: γ-knife, radio-wave knife (also known as Cyberknife, computer knife or network knife), spiral tomography radiotherapy system are all stereotactic radiotherapy, which is a perfect combination of computer technology, tumor real-time tracking technology and radiotherapy technology. They are not a tangible knife, they are focused radiation energy to produce a scalpel-like effect. They all have certain efficacy in the treatment of liver cancer, but it is necessary to avoid blindly expanding the indications. (6) High-powered ultrasound focusing: (ultrasonic knife) is generally applicable to tumors below 3cm, and it focuses ultrasound to produce heat to destroy tumors, so it has little impact on liver function. The limitation is that there should be no gas or rib blockage in the area where ultrasound passes. (7) Systemic therapy: ① including systemic chemotherapy, immunotherapy, anti-angiogenic therapy, targeted therapy, Chinese medicine; ② mainly applicable to: advanced patients who have developed extrahepatic metastasis, although localized lesions, but not suitable for surgical resection, radiofrequency or microwave ablation and TACE treatment, or those who fail to progress in local treatment; diffuse hepatocellular carcinoma; combined with portal vein trunk cancer thrombosis and/or inferior vena cava cancer thrombosis. (The above patients require essentially normal or near-normal liver function Child-Pugh grade A or B); (3) for patients with severe liver insufficiency Child-Pugh grade C), symptomatic supportive therapy is the only option; (4) available evidence suggests that systemic therapy is superior to symptomatic supportive therapy; it can reduce tumor load, improve tumor-related symptoms and improve quality of life, and also prolong survival time and (5) HCC is a tumor with some sensitivity to new chemotherapy regimens including oxaliplatin; (6) Arsenious acid injection (arsenic trioxide, As2O3) has been approved by the State Food and Drug Administration (SFDA) to increase the indications for advanced hepatocellular carcinoma; (7) Sorafenib is the first targeted drug approved for hepatocellular carcinoma in Europe, the United States and China, but its limitations are The limitations of sorafenib are: prolonged survival time is only more than 3 months; adverse reactions are large; expensive (about RMB 50,000 per month); requires patients with Child-PughA or relatively good grade B liver function; ⑧ Chinese medicine can help reduce the toxicity of radiotherapy and chemotherapy, improve cancer-related symptoms and quality of life, and possibly prolong survival, and can be an important adjunct to liver cancer treatment; ⑨ Immunotherapy such as application of thymidine α1 can enhance the immune function of patients with adjuvant antiviral and antitumor effects. (8), treatment of underlying diseases (cirrhosis and hepatitis) and various complications: ① For HCC patients with hepatitis B and/or C viral hepatitis background, special attention should be paid to check and monitor the viral load (HBV-DNA/HCV-RNA), if the hepatitis virus is actively replicating, active antiviral therapy must be used, nucleoside analogues, interferon and its long-acting preparations and thymidine α1, etc. One study found that for patients with HBV-DNA <104 copies/ml, both (with lamivudine or adefovir) can prolong the survival time of patients after hepatocellular carcinoma surgery. However, the need for antiviral therapy for HBV-DNA <104 copies/ml has yet to be studied. Other treatments include: protection of liver function, cholestasis, improvement of nutritional status, glycemic control for patients with combined diabetes, correction of anemia, correction of hypoproteinemia, prevention and control of gastrointestinal bleeding, etc. These treatments can help ensure the smooth implementation of anti-tumor therapy and its therapeutic effect. In conclusion, in clinical practice, the appropriate initial treatment should be selected with comprehensive and integrated consideration of factors such as tumor, liver function, systemic condition, viral load, technical strength of the unit, patient's willingness and economic situation. The number of tumors is more important than the size, and surgery or transplantation is generally not an option if the number of tumors is 4 or more. Once there are lymph node metastasis, vascular invasion or distant metastasis, transplantation will not be considered. 4.Treatment standard should be followed and clinical innovation is not possible. The treatment standard is to guide the clinical treatment in hospitals at all levels; of course, any standard is not mechanical or unchanging. The progress of medicine needs innovation, innovation should break the norms and break through the routine; innovation and breakthrough need to have a good foundation, clinical workers should be encouraged to do some research beyond the diagnosis and treatment routine, so that medicine will develop and more patients can benefit from it.