Does liver cancer come quietly? Why is early liver cancer painless? Read more →

Currently, liver cancer ranks fourth in incidence among common malignant tumors in my country, and has been ranked second for many years in the "ranking list" of cancer-related deaths in my country, posing a serious threat to the lives and health of the Chinese people.

Although hepatologists attach great importance to early screening of liver cancer, the early diagnosis rate of liver cancer is very low, resulting in a much higher mortality rate of liver cancer than other tumors . The reason is that liver cancer has no symptoms in the early stage and it is difficult to detect through the patient's own feelings.

Why doesn’t early liver cancer cause pain?

Netizens who have watched the movie "Jiao Yulu" will remember the scene in which Jiao Yulu used the armrest of a chair to support his liver to stop the severe pain after suffering from liver cancer, but not all liver cancer patients will feel pain in the liver area . The most common early manifestations of liver cancer are some featureless and non-directional manifestations, which are common in the early stages of many cancers or chronic wasting diseases, such as: weight loss and lack of strength, which are the most common .

Pain in the liver is a localized manifestation of liver cancer. However, pain in the liver is often not obvious in the early stages. It only becomes obvious in the late stages when the liver cancer has grown very large.

There are two important characteristics of the pain of liver cancer: the first is that it does not hurt when it is small , but it hurts when it is large . The second characteristic is that it may be cured when it is painless, but it cannot be completely cured when it hurts . Why do we say this? Because the liver has no pain nerves , when liver cancer grows in the liver when it is very small, people cannot feel any pain. Therefore, if regular check-ups are not done, small liver cancers will not be found. Once liver cancer grows particularly large, with a diameter of more than 10 cm, it is possible that the membrane wrapped around the liver, which we call the liver capsule, will be stretched due to the increase in the volume of the liver. There are pain nerves on the liver capsule , so when the liver capsule is stretched, it is like a balloon filled with air, and its surface tension will become greater and greater, and its pain will become more and more intense . By that time, the liver cancer will be a large liver cancer that cannot be cured .

Therefore, the characteristics of liver cancer pain are like this. When there is no pain, it may be cured, but when there is pain, there is probably no chance of a radical cure .

High risk factors for liver cancer

1. Hepatitis B

Hepatitis B can cause liver cancer. There are two ways in which hepatitis B causes liver cancer:

First of all, the hepatitis B virus can be integrated into the genome of human liver cells . If the integration site happens to be at the key site that can activate oncogenes or block tumor suppressor genes , it will cause liver cancer.

Secondly, repeated attacks of hepatitis B lead to liver fibrosis , which eventually progresses to cirrhosis . In the cirrhosis stage, liver cells grow disorderly , causing many liver cells to become malignant and cause liver cancer .

2. Drinking

This is a liver damage factor with clear evidence , and can be the sole cause of death from cirrhosis and liver cancer. Existing data confirms that men who consume 40 grams of alcohol per day (half for women) are at risk of alcoholic liver disease after 5 years . If no intervention is taken, the ultimate outcome of alcoholic liver disease is cirrhosis and liver cancer.

40 grams of alcohol is really not a lot! According to the conversion formula of alcohol, 40 grams of alcohol is only 2 liang of 50-proof liquor or 2 bottles of beer . Therefore, quitting drinking is a very important liver care skill. It is best not to drink at all. If you drink, only drink at parties and don't drink when you are alone. This also requires caution!

3. Obesity

Fatty liver has become the most common liver disease in China , with an urban incidence rate of 20-30%, far surpassing hepatitis B. The cause of fatty liver is even simpler. When you eat a lot and exercise little , fat accumulates in your body. Not only will you have a thick belly and thighs and a poor figure, but your liver will be the first victim, called fatty liver. Even if you effectively control heart disease, cerebrovascular disease, and diabetes caused by obesity, fatty liver still has the chance to develop into cirrhosis and liver cancer. Moreover, fatty liver is not as easy to treat as cardiovascular and cerebrovascular diseases. There is no specific treatment drug at present , and you can only rely on losing weight!

4. Aspergillus

Aflatoxin is a highly toxic liver carcinogen , among which aflatoxin B1 can cause cells to incorrectly repair DNA, leading to serious DNA mutagenesis. Epidemiological surveys on liver cancer in China have found that the level of aflatoxin contamination in the diet of people in certain areas is positively correlated with the incidence of primary liver cancer. In 1993, aflatoxin was classified as a naturally occurring carcinogen by the Cancer Research Institute of the World Health Organization (WHO), which is a highly toxic substance. Aflatoxin mainly contaminates grains, oils and their products , such as peanuts, peanut oil, corn, rice and cottonseed. How to detect liver cancer early?

The so-called early liver cancer generally has no symptoms . It is a single liver cancer with a diameter of less than 3 cm that is discovered through imaging examinations. This type of liver cancer can be cured through surgery or minimally invasive radiofrequency ablation . The future life expectancy and quality of life of patients with early liver cancer who undergo appropriate radical surgery are exactly the same as those who have never had liver cancer. Therefore, regular review of people at high risk of liver cancer is the most effective way to detect small liver cancers early and thus obtain a radical cure. So, how can liver cancer be detected early?

When liver cancer is very small, the human body cannot feel it, so how can we detect small liver cancer? We need to conduct regular screening for high-risk groups. The most effective, reliable, and cost-effective way to screen liver cancer now is to perform a liver ultrasound and a blood test for alpha-fetoprotein every six months . Combined testing of ultrasound and alpha-fetoprotein can detect small liver cancers with a minimum diameter of about one centimeter; the detection rate of small liver cancers can also reach 60-70%. During the examination, whether there is an abnormality in ultrasound or hepatitis A protein , further enhanced CT or enhanced MRI scans should be performed, which are the most effective means of detecting early liver cancer.

Even with the early screening technology mentioned above, there will still be a 30% missed diagnosis rate. How can we find these missed patients? There are many so-called "early cancer screening" new methods. For example, in addition to alpha-fetoprotein, there are some other new liver cancer markers : abnormal prothrombin, alpha-fetoprotein isomers, and even some genetic testing methods, which may help the discovery of early liver cancer. However, these testing methods are relatively expensive . When to do it and for whom to do it are still worth exploring. How to treat liver cancer?

If it can be detected early, liver cancer can be cured. Single liver cancer lesions with a diameter of less than 3 cm can be completely cured through surgical resection . There is no need to open the abdomen for surgical surgery. All you need to do is laparoscopic minimally invasive surgery, make a few small holes, and put a very small endoscope into the abdominal cavity to completely remove the small liver cancer. If the diameter exceeds 3 cm or there are more than 3 lesions, then liver cancer has lost the chance of being cured and can only be treated with palliative treatment . The so-called palliative treatment means that although liver cancer cannot be eradicated and liver cancer patients are free of cancer cells all over their bodies, through a series of systemic treatments, such as radiotherapy, chemotherapy, minimally invasive treatment, targeted therapy, and immunotherapy, these comprehensive treatments can allow patients with liver cancer that have metastasized to survive for a long time, improve their quality of life, and prolong their life. For advanced liver cancer that has already undergone extensive systemic metastasis, molecular targeted drugs (such as sorafenib and lenvatinib) combined with immune checkpoint inhibitors (such as PD-1/PDL-1 monoclonal antibodies) can now be used to control disease progression in the long term.

Summarize:

Liver cancer is a malignant tumor caused by multiple factors (such as hepatitis B, drinking, obesity, and aflatoxin); for high-risk groups, liver ultrasound and alpha-fetoprotein screening should be performed every six months to facilitate early detection and treatment. Single liver cancers with a diameter of less than 3 cm can be cured by surgery.

Reference Links:

[1] Department of Medical Administration, National Health Commission of the People's Republic of China. Guidelines for the diagnosis and treatment of primary liver cancer (2019 edition)[J]. Journal of Clinical Hepatobiliary Diseases, 2020, 36(2): 277-292.

[2] JORGE A. MARRERO, LAURA M. KULIK, CLAUDE B. SIRLIN, et al. Diagnosis, staging, and management of hepatocellular carcinoma: 2018 Practice Guidance by the American Association for the Study of Liver Diseases. Hepatology, 2018, 68 (2): 723-750.

[3] Liver Cancer Committee of Chinese Anti-Cancer Association. Expert consensus on multidisciplinary comprehensive treatment of liver cancer in China[J]. Journal of Clinical Hepatobiliary Diseases, 2021, 37(2): 278-285.

[4] Molecular Diagnostics Group of the Chinese Medical Association, Laboratory Medicine Branch. Expert consensus on biomarker detection and application of hepatocellular carcinoma[J]. International Journal of Laboratory Medicine, 2020, 41(24): 2945-2948.

Author: Yan Jie, Chief Physician of the Liver Disease Center of Beijing Ditan Hospital, Associate Professor of Peking University School of Medicine, and Master's Supervisor

Review | Tang Qin, Chief Researcher, Science Popularization Department, Chinese Medical Association