Because the vast majority of liver cancer in China is a consequence of hepatitis B virus infection, the incidence is high. Hepatitis B virus infection usually occurs in infancy, and most of them become chronic carriers; 25% of them develop chronic hepatitis B in adulthood; without antiviral treatment, about 40% of them develop cirrhosis after middle age; if a patient with cirrhosis still carries the virus and has active disease, liver cancer will occur in 1% to 4% every year. A rough calculation can be done: if a person gets cirrhosis at the age of 40 and lives to 70, what are the chances of getting liver cancer in 30 years? Why should the diagnosis of liver cancer start with screening tests? Liver cancer is a very malignant tumor. If you go to the doctor only when you have the symptoms of liver cancer, most of them are already giant liver cancer and it is not an indication to change a liver. The liver cancer that can be cured is mainly “small liver cancer”, which you have to go to it; if it comes to you, the treatment is probably already very difficult. What is meant by “small liver cancer”? It is not just because it is small, but because it is a specific stage of liver cancer development. The diameter of small liver cancer should be less than 3 centimeters. At this time, it has an intact envelope and the cancer cells have not yet invaded the blood vessels in the liver, so as long as it is removed, it is almost a cure. If it is more than 3 cm, it is likely that the cancer cells have already invaded the blood vessels inside the liver or even metastasized outside the liver, even if it is removed, most of them will recur. Patients who have no symptoms of “small liver cancer” but have the possibility of developing liver cancer, that is, those who have the possibility of developing liver cancer, should be checked regularly: ultrasound and methemoglobin should be checked every 6 months. It is called “screening test” to start checking for liver cancer when there is no liver cancer. How to confirm the diagnosis of liver cancer? Ultrasound can only detect suspicious nodules, but CT or MRI is needed to confirm the diagnosis, which is usually possible if the contrast agent is “fast in and fast out”. In general, no puncture is done for liver cancer diagnosis, because it is difficult to reach cancer nodules less than 3cm, and it may cause tumor spread on the way of the puncture needle. How to choose treatment? If you can afford resection surgery, surgery is the best treatment; if you have severe cirrhosis or are in poor health and cannot afford surgery, you can have radiation therapy called “photon knife”.