Liver cancer is the spread and growth of unhealthy cells in the liver. The liver is a football-sized organ that sits in the upper right portion of the abdomen, above the stomach and beneath the diaphragm.
Various types of cancer can form in the liver. The most common type of liver cancer is hepatocellular carcinoma, which starts in the main type of liver cell – hepatocyte. Some other types of liver cancer, like hepatoblastoma and intrahepatic cholangiocarcinoma, are less common.
Cancer that spreads to the liver is more common and known than cancer that forms in the liver cells. Cancer that begins in another area of the body — like the lung, colon or breast— and then spreads to the liver is called metastatic cancer rather than liver cancer. This type of cancer is usually named after the organ in which it began — such as metastatic colon cancer to describe cancer that starts in the colon and spreads to the liver. As per the data from 21 population based and seven hospital based cancer registries, the age adjusted incidence rate of liver cancer in India is 0.2-2.2 for women and 0.7-7.5 per 100,000 persons per year for men.
Types of liver cancer
- Primary liver cancer – It is a type of cancer that starts in the tissue of the liver. It has two main sub-types:
- Hepatocellular Carcinoma – It means the formation of cancer cells in the tissues of the liver. It is a very common type of liver cancer. Fibrolamellar hepatocellular carcinoma (FHCC) is a very rare form of this disease. Fibrous bands throughout the cells of the tumor help the doctors diagnose FHCC.
- Cholangiocarcinoma or Bile duct cancer – Cholangiocarcinoma is a type of liver cancer that forms in the ducts that drain bile from the liver to the small intestine. It is an extremely rare form of primary liver cancer.
- Secondary metastatic liver cancer – It occurs when cancer spreads to the liver from other parts of the body. Secondary cancer is composed of the same type of cells as the primary cancer. If the cancer started in the lung and has spread to the liver, the areas of cancer in the liver are comprised of lung cancer cells. The most common types of liver metastasis are:
- Gastrointestinal cancers
- Colorectal cancers
Most people do not have symptoms and signs in the early stages of primary liver cancer. When they do appear, it may include:
- Loss of appetite
- Losing weight without trying
- Upper abdominal pain
- Vomiting and nausea
- Fatigue and general weakness
- Abdominal swelling
- Yellow discoloration of the skin and the whites of your eyes (jaundice)
- White, chalky stools
Causes and diagnosis
Liver cancer occurs when liver cells develop changes in their DNA. A cell’s DNA is the material that provides instructions for every chemical process in the body. DNA mutations result in changes in these instructions. One of the results is that cells may begin to grow out of control and eventually form a tumor.
Sometimes the cause of liver cancer is known, like with chronic hepatitis infections. But sometimes it happens in people with no underlying diseases and it is not clear what causes it. Procedures and tests are done to diagnose liver cancer:
- Blood tests – Blood tests may reveal liver function abnormalities.
- Imaging tests – The doctor may recommend imaging tests, such as CT, MRI, or an ultrasound.
- Removing a sample of liver tissue for testing – Sometimes it is necessary to remove a small piece of liver tissue for testing in order to make a definitive diagnosis of liver cancer.
During a liver biopsy, the doctor inserts a thin needle through the skin and into the liver to obtain a tissue sample. In the laboratory, doctors examine the tissue under a microscope to find cancer cells. Liver biopsy carries a risk of bruising, bleeding, and infection.
Stages and treatment options
Patients with normal liver function are defined as class A; those with mild abnormalities are class B; and those with severe abnormalities are class C. Generally, patients with class C cirrhosis are deemed not fit to receive treatment.
- Stage 1 – The single primary tumor (any size) has not grown into any blood vessels. It has not spread to the distant sites or nearby lymph nodes.
- Stage 2 – A single primary tumor (any size) has grown into the blood vessels; or several small tumors are present, all less than five centimeters in diameter. The cancer has not spread to the distant sites or nearby lymph nodes.
- Stage 3 – This stage has three sub-types:
- Stage 3A – Various tumors have been found, and at least one is larger than five centimeters. The cancer has not spread to the distant sites or nearby lymph nodes.
- Stage 3B – Various tumors have been found, and at least one tumor is growing into a branch of the hepatic vein or portal vein. The liver cancer has not spread to the distant sites or nearby lymph nodes.
- Stage 3C – The tumor has grown into the outer covering of the liver, or the tumor has grown into a nearby organ (other than the gallbladder). It has not spread to the distant sites or nearby lymph nodes.
- Stage 4 – The cancer has spread to nearby lymph nodes and may have grown into nearby organs or blood vessels. Advanced liver cancer does not often metastasize, but when it does, it is most likely to spread to the bones and lungs. Stage 4 liver cancer may be:
- Any T, N1 and M0, meaning the cancer consists of any size or number of tumors in the liver, and it has spread to nearby lymph nodes. However, no evidence has been found that the cancer has spread to distant tissue or organs.
- Any T, any N and M1, meaning the cancer consists of any size or number of tumors in the liver. However, the cancer may or may not have grown into the lymph nodes and it has spread to some other part of the body.
Surgery that fully removes the tumors is the only way to improve the chance of recovery for people with early stage liver cancer. The options include:
- Partial hepatectomy – When the tumor is tiny and occupies a limited section of the liver, a surgeon can remove only this part of the organ to stop the cancer from growing and spreading. People with liver cancer also have cirrhosis (scarring of the liver). In this case, a surgeon needs to leave enough healthy tissue after hepatectomy so that the liver can function. Liver surgery of this scale can lead to blood clotting issues and excessive bleeding, as well as pneumonia and infections.
- Liver transplant – Patients for a liver transplant must have a tumor smaller than 5 centimeters or several tumors smaller than 3 cm each. A successful transplant restores normal liver function and reduces the risk of cancer returning. However in certain cases, the immune system may reject the new organ, attacking it as a foreign body.
Advanced liver cancer, including where it has spread to other areas of the body, has a low survival rate. Treatment options may differ, depending on the type of liver cancer:
- Ablative therapy – A surgeon can use radio waves, electromagnetic waves and heat, or alcohol directly on the tumor to shrink it or prevent its growth. Destroying a tumor by freezing, also known as cryoablation, may also be possible
- Radiation therapy – A surgeon directs radiation at the tumor or tumors, killing a significant number of them
- Chemotherapy: A surgeon injects drugs into the bloodstream or a main blood vessel in the liver to kill cancer cells
Side effects of treatment
The common side effects of treatment of liver cancer may include:
- Hair loss
- Loss of appetite
- Mouth sores
- Nausea and vomiting
- Increased chance of infections from low white blood cell counts
- Easy bleeding or bruising from low blood platelet counts
- Fatigue from low red blood cell counts
Survivorship and prevention of liver cancer
A liver cancer diagnosis and treatment can be overwhelming. It is important to have a strong support system that can help you deal with any stress or anxiety you may be feeling. You may want to consider joining a cancer support group where you can discuss your concerns with others who can relate to what you are going through. You might also want to speak to a counselor who can help you work through the emotions.
Liver cancer has a low survival rate in comparison to others cancers. However, you can reduce the risk of experiencing the disease by following some of the measures mentioned below:
- Moderating alcohol intake – Regularly consuming high volume of alcohol on a long term significantly increases the risk of liver cancer and cirrhosis. Moderating or abstaining from alcohol can significantly reduce the risk.
- Limiting tobacco use – This can help avoid liver cancer, especially in people who have hepatitis C and B.
- Having a hepatitis B vaccination – The following people should consider having the vaccine:
- People who depend on drugs and share needles
- Individuals who engage in unprotected sex with many partners
- Dentists, doctors and nurses and other medical professionals whose work increase their risk of infection
There is no definite way to prevent hepatitis C and no vaccination against the virus.
- Maintaining a healthy body weight – Obesity is a risk factor as fatty liver disease and cirrhosis can result in liver cancer and diabetes.
- Treating underlying conditions – Some other conditions can lead to liver cancer like hemochromatosis and diabetes. Treating them before they develop into liver cancer can reduce the risk of complications.