The liver, the largest gland in the body, plays a vital role in keeping us alive. Its many functions include storing vitamins and nutrients, producing proteins used for blood clotting, and creating bile used for digestion. It also breaks down and filters out toxins from the blood.
2 types of cancer affect the liver:
In Canada, it is estimated that about 3,500 people will be diagnosed every year with liver cancer, and about 3 times more men than women are affected. Around 1,650 people die from liver cancer each year, equal to around half the number of people diagnosed annually.
The causes of liver cancer are still unknown, but some risk factors have been identified. They include:
Liver cancer can go undetected for quite a while before there are any indications that something might be wrong. Most of the symptoms are a result of liver damage. They include:
To make the diagnosis, a thorough medical history must be taken, followed by a physical examination. Your doctor may then recommend some of the following tests:
Once cancer has been diagnosed, your doctor will need to "stage" or classify the cancer in order to recommend the proper treatment.
The classifications are done by the TNM system:
Some doctors stage liver cancer according to the following categories:
A variety of other classifications are used in some centres to help predict overall prognosis as well as to determine the ability to undergo surgery.
As with most cancers, there are three forms of treatment available for liver cancer: surgery, chemotherapy, and radiotherapy. The treatments can be combined with one another.
For localized resectable cancer (small T number, N0, M0), the treatment is usually surgery. This involves removing the tumour and, perhaps, some surrounding tissue. The liver is a unique organ in that it can regenerate its cells and continue to function as before. Chemotherapy may be offered after surgery to kill cancer cells that may have been left behind.
The cancer can also be destroyed in place through cryosurgery or ethanol ablation. For cryosurgery, the surgeon uses a metal probe to freeze the cancer cells. A small incision is made and the probe, which has liquid nitrogen circulating in the tip, does the freezing. In ethanol ablation, the surgeon injects alcohol directly into the tumour, either through the skin or during a surgical procedure.
Removal of the entire liver isn't an option, as the liver is essential to survival. In the past, those with cancer weren't candidates for liver transplants; however, surgeons are now learning that some people with early liver cancer can benefit from a transplant. With a successful transplant and proper medical care, the recipient can go on to lead a healthy life.
For localized unresectable cancer (higher T number, N0, M0), the location of the tumour doesn't allow for surgical removal. This may be because it's situated in a very sensitive area or because it is affecting too much of the liver. The treatment options include cryosurgery, chemotherapy, targeted therapy (medication to reduce tumour blood supply and block tumour growth and spread), liver transplant, radiation therapy, radiofrequency ablation, or ethanol ablation.
Chemotherapy uses medications to kill the cancer cells. The medications are usually given intravenously (injected directly into the blood), but some are available in a pill form to be taken orally. One difficulty with treating liver cancer is that many medications are metabolized (broken down) in the liver, so the options may be limited.
Chemotherapy medications circulate throughout the body, so the side effects, although temporary, can affect many different areas of the body. They include:
Another form of chemotherapy, called hepatic artery infusion, allows the medications to go directly to the liver. A small pump is placed directly under the skin and delivers the medications directly into the artery leading to the liver. This type of treatment decreases the side effects, since the medications are delivered in a more focused manner and don't spread as much through the rest of the body. Researchers haven't found that this type of treatment is more effective in treating liver cancer than the normal way of giving chemotherapy, but it does seem to increase the quality of life among those with liver cancer.
A procedure called chemoembolization might be considered for a tumour that can't be removed surgically. Material that has been saturated with chemotherapy medications is injected into the blood vessels that supply nutrients to the tumours. By cutting off their fuel, it kills the cancer cells.
Radiation therapy (radiotherapy) is an external treatment that kills the cancer cells. It's aimed directly at the tumours in an effort to shrink them. In some cases, radiotherapy might be done before surgery to shrink the tumours, making them easier to remove. Radiotherapy isn't used very often to treat liver cancer, as the tumours tend not to respond to radiation and the liver itself is very sensitive to it.
For people treated with radiotherapy, there are several possible side effects. They include:
Advanced liver cancer (N1 and/or M1) is more difficult to treat, as it has spread to other parts of the body. In these cases, chemotherapy and radiotherapy might be options. "Targeted therapy" medications, such as sorafenib, may help certain patients live longer.
People who have recurrent liver cancer will have their treatment based on what has already been done and how far the cancer has developed.
Liver cancer can't be prevented, but with understanding of the risk factors involved, it might be easier to detect in its early stages. People who fall in the high-risk groups, such as those who have hepatitis or cirrhosis, should be screened regularly with either ultrasounds or blood tests. Blood tests can show the level of liver enzymes, which tells doctors how well the liver is working.