Liver cancer occurs when abnormal cells grow out of control in the liver tissue. There are two main types of liver cancer. A distinction is often made based on where the liver cancer started. So-called “primary” cancers are distinguished from metastatic cancers. Primary liver cancers originate from liver cancer cells while metastatic cancers are tumors that appear elsewhere in the body and then migrate into the liver.
Primary liver cancers develop mainly in a liver already affected by another disease such as cirrhosis. Cases in a person with a healthy liver are very rare.
Metastatic cancers are 20 to 50 times more frequent than primary cancers. The explanation lies in the purifying function of the liver which drains and filters all the blood of the body. For example, when a lung tumor releases cancer cells into the blood, there is a good chance that these cells will nestle and grow in the liver.
Located on the right side of the abdomen, below the diaphragm and to the right of the stomach, the liver is one of the largest organs in the human body. Its functions are multiple and important:
- It filters the toxins absorbed by the body.
- It stores and transforms the nutrients absorbed by the intestines.
- It makes proteins that help the blood to clot.
- It produces bile which helps the body to absorb fat and cholesterol.
- It helps regulate the level of glucose (blood sugar) and certain hormones.
Symptoms of liver cancer
At the onset of the disease, liver cancer very rarely triggers specific and obvious symptoms. It is therefore difficult to diagnose the disease at an early stage. This cancer is more often detected when it has reached an advanced stage. At this point, it can manifest itself with the following symptoms:
- Unexplained weight loss;
- Loss of appetite;
- Pain in the abdomen;
- Nausea and vomiting;
- Generalized fatigue;
- The appearance of a lump in the liver area;
- Jaundice (yellow complexion and eyes, pale stools and dark urine).
Be careful, these symptoms do not necessarily indicate the presence of a cancerous tumor. They can be signs of other more common health problems. If such symptoms appear, it is important to consult a doctor so that he can do the appropriate examinations and determine the cause, especially for those at risk.
People at risk
- People with chronic hepatitis B or C
- Patients with cirrhosis of the liver regardless of its origin;
- Those who consume alcohol in excess.
- People with diabetes.
- People with obesity.
- People suffering from an iron overload
- People with an overload of fat in the liver
Most liver cancer develops in a context of cirrhosis (4 times out of 5).
Cirrhosis is a disease corresponding to a set of irreversible and diffuse lesions of the liver. The liver is irreversibly damaged after chronic exposure to toxic compounds such as alcohol or infectious agents (hepatitis B and C). In this disease, liver tissue is replaced by fibrosis which distorts the architecture of the liver and forms nodules. When the liver is cirrhotic, it can no longer perform its functions normally. Hepatic cirrhosis is always definitive and does not improve.
- The viruses that cause hepatitis B and C (HBV and HCV) are the cause of most hepatocellular carcinomas, as they cause “chronic” liver disease. The attacked cell regenerates, or heals, but in an abnormal form (fibrosis), which leads to cancer. However, 10 to 30% of hepatocellular carcinomas induced by hepatitis B develop in the absence of fibrosis or cirrhosis. Hepatitis A, on the other hand, is not a risk factor because it is an “acute” disease.
- Cirrhosis of the liver is the other major cause of liver cancer. It is most often due to excessive alcohol consumption, but can also occur as a result of chronic liver disease (chronic viral hepatitis, autoimmune disease, iron overload, etc.).
- Aflatoxin, a toxin produced by a type of mold that forms on improperly stored agricultural produce, is a carcinogen that may contribute to the development of a liver tumor.
- Vinyl chloride, used in the manufacture of some plastics, is known to be a carcinogen that can cause hepatoma.
- Arsenic, used to treat wood, as a pesticide or in some metal alloys, is a poison that can trigger the formation of a liver tumor.
- Excessive and long-term alcohol consumption causes inflammation of the liver and lesions that progress to cirrhosis. However, a patient with cirrhosis has an estimated risk of between 1 and 5% of developing liver cancer each year. This is why after 5 years, this disease has a cancer risk of 5 to 25%. The risk is estimated to increase when consumption reaches or exceeds one drink per day.
- NASH (Non-Alcoholic Fatty Liver Disease) is a disease found most often in overweight or obese patients, diabetics and patients with high triglyceride levels. Excess fat produces chronic inflammation that can lead to cirrhosis and therefore hepatocellular cancer.
As with most cancers, it is important for the treatment of liver cancer to detect it as early as possible. For this reason, if you have any of the above risk factors (liver cirrhosis, chronic hepatitis B or hepatitis C, iron storage disease, etc.), you should get screened at regular intervals. This should be done in the case of cirrhosis approximately every six months and should include an ultrasound examination.
The ultrasound examination of the liver often gives the first indication of the presence of liver cancer. The determination of the alpha-fetoprotein in the blood has only a low sensitivity and is no longer generally recommended as a monitoring examination in patients with cirrhosis of the liver.
If the ultrasound examination reveals a suspicion of a cancer in the liver, a more precise X-ray, such as a computed tomography (CT) or magnetic resonance imaging (MRI), is carried out, in which the diagnosis can be made and the exact number and extent of the cancer flock can be determined.
If no clear diagnosis is possible due to the imaging, the removal of a tissue sample from one of the flocks by a needle puncture under ultrasound vision is usually carried out for a reliable diagnosis.
Treatment of liver cancer
When possible, surgery is the first choice of treatment and consists of a “partial hepatectomy”, which is the removal of part of the liver. Various conditions must be met: the tumor must be small (<3cm) and single. It should be easily accessible and care should be taken to ensure that the volume of healthy liver remaining is sufficient to ensure normal liver function.
The liver tissue has the capacity to regenerate itself, at least partially. Thus, in the weeks following the partial hepatectomy, the size of the liver will increase. However, the liver will never return to its original size.
Surgical treatment may consist of a “total hepatectomy” followed by a transplant, ideal treatment if possible. The diseased liver is completely removed, and replaced with an entire liver, or liver lobe, from a compatible donor. Note that it is rare that it is possible to perform a liver transplant to treat primary liver cancer. The wait is indeed very long, (6 months minimum), and the conditions required for the feasibility of the transplant are often exceeded.
Radiofrequency ablation RFA)
When removal of the tumor by surgery is not possible, or the waiting time for a graft too long, radiofrequency ablation is the first-line local therapeutic approach. This technique involves inserting small electrodes into the liver to cause a discharge of high-frequency waves that induce ionic movements, leading, through a thermal phenomenon, to necrosis by coagulation of abnormal cells (cell death). Depending on the case, it is performed under local or general anesthesia.
Targeted therapies are increasingly used to combat factors that contribute to tumor growth. For example, antiangiogenic agents block the formation of new blood vessels (angiogenesis) that allow the tumor to grow. This type of therapy shows great promise and has aroused a lot of interest and hope in the medical community.
Cryosurgery is no longer used today, due to the emergence of techniques for destroying liver tumors by heat (mainly radiofrequency). This technique involved inserting a probe containing liquid nitrogen at –200 °C into the liver to cold burn the cancer cells.
This technique causes water molecules to move in the cells, reaching a very high temperature, 100 °C, in seconds. It is still little used, and under evaluation with regard to radiofrequency.
Chemical method: percutaneous injection
This other approach remains possible, but is used less and less. It involves destroying one or more small tumors by injecting them with ethanol or acetic acid. This has the effect of dehydrating them and causing their necrosis (cell death). This procedure can be performed under local anesthesia and can be repeated if the tumor does not disappear entirely.
Chemotherapy represents a solution when surgery or techniques for local destruction of the tumor are not possible, or in the event of recurrence.
In the event that the primary liver cancer is extensive (measuring more than 3 cm, with several lesions, but on the same side of the liver, it is sometimes possible to inject into the artery that supplies the tumor with beads containing chemotherapy drugs directly into the tumor, which helps to reduce side effects.
Radiation therapy is very rarely used to treat primary liver cancer. This type of cancer is not very sensitive to radiotherapy.
Prevention of liver cancer
It’s impossible to prevent liver cancer for sure, but it is possible to reduce your chances of developing it by protecting yourself against hepatitis B and C viruses. To learn about the various ways to prevent these infections, see our Hepatitis dossier. It is possible, for example, to receive a vaccine against the hepatitis B virus. The vaccine has reduced the frequency of Hepatitis B (HBV), and also the incidence of Hepatocellular carcinoma (HCC) in heavily affected regions. In Europe, Italy, the number of HBV infections and HCC cancer has fallen sharply thanks to vaccination.
There is no vaccine against hepatitis C, so hygiene measures and protection during sexual intercourse (condoms) should be emphasized. It is transmitted through the blood.
Excessive alcohol consumption should be avoided. Cirrhosis of the liver, chronic alcoholism is an important risk factor for hepatocellular carcinoma. Regular monitoring of anyone with a binge drinking habit is essential.