Liver tumors can be diagnosed using a combination of blood tests and other diagnostic tests. Blood tests look at liver function and levels of tumor markers (certain substances which are linked to specific types of cancer). Liver tumors will often show on an ultrasound scan but full assessment requires a CT (computerized tomography) scan or MRI (magnetic resonance imaging) scan. If the results from blood tests and CT or MRI scans are not obvious, a needle biopsy using ultrasound (or other imaging) guidance will usually confirm the diagnosis. The following sections provide more detailed information on the following tests and procedures which may be used to detect (find) and diagnose liver cancer.
Physical exam and history
Your doctor will examine your body to check your general health, including any signs of disease (such as lumps or weight loss) or anything else that seems unusual. The doctor will also take a history of your health including past illnesses and treatments and will ask about your symptoms (the things you experience about your illness, eg, tiredness, loss of appetite).
This test uses high frequency sound waves which bounce off your internal organs and tissue to create a picture of a part of the body. The scan will show any abnormal growths in your liver. You may be asked not to eat or drink for at least four hours before the scan. The scan takes only a few minutes and is painless. You usually sit or lie near the ultrasound machine. A clear gel is spread on your skin over the area that will be scanned. The gel helps to transmit the sound waves. You can usually go home as soon as the scan is over.
CT (computerized tomography) scan
A CT scan makes a series of x-rays of areas inside the body. This series of cross sections or "slices" through the part of the body being scanned are used to build a very detailed three-dimensional picture of the inside of the body. This type of scan may be used to look for signs of cancer in your liver (using a CT scan of your abdomen) and for cancer in other parts of your body. A CT scan can give a very accurate picture of the location and size of a tumor. It can also show how close major body organs are to the area that needs to be treated or operated on. A contrast medium (dye) may be injected partway through the scan to help show more details of your liver and the tumors. A CT scanning machine is large and "doughnut" shaped. You lie on a bed that can slide backwards and forwards through the hole of the machine. The pictures are taken as you move through the machine. An abdominal CT scan takes from 10 to 30 minutes and is painless. You can usually go home as soon as the scan is over.
CT is also called computed axial tomography (CAT).
MRI (magnetic resonance imaging) scan
An MRI scan is similar to a CT scan but uses magnetic fields instead of x-rays to build up a series of cross sections through the part of the body being scanned. An MRI scan will be clearer than a CT scan for some types of tissues. Your doctor will know the best scan for you.
The MRI scanner is a large cylinder with a bed that can move backwards and forwards through the cylinder. The images are taken inside the cylinder. You will need to remove all metal belongings before going into the room because the cylinder is a very powerful magnet. You may have an injection of a contrast medium (dye) just before the scan. This dye helps to show body tissues and organs more clearly on the scan. MRI is painless but the machine is very noisy. You may be given earplugs or headphones to wear. The test may take between 1 and 1.5 hours. You are usually able to go home as soon as the scan is over.
MRI is also called nuclear magnetic resonance imaging (NMRI).
PET (positron emission tomography) scan
A PET scan uses low-dose radioactive sugar to measure the activity of cells in different parts of the body. Cancers rely on sugar for their energy and usually use it more rapidly than normal tissues. This means that radioactivity accumulates in the cancer(s), and shows up as a "hot spot" on the scan. The PET scan can be used to detect tumors as small as 1cm. The radioactivity decays within a very short time and only stays in the body for a few hours. A PET-CT scan is a test that is completed with the aid of a CT scan performed on the patient during the same session, in the same machine.
Serum tumor marker test
A sample of your blood is taken and tested to measure amounts of certain substances released into your blood by organs, tissues, or tumor cells in your body. Certain substances, called tumor markers, are linked to specific types of cancer when they are found in higher levels than usual in the blood.
CEA (carcinoembryonic antigen) is very high in patients with secondary colorectal cancer in the liver (it may also be elevated in people with other cancers of the digestive system, lung, and breast and in some non-cancerous diseases and in otherwise healthy smokers).
Not every person with liver tumors will have higher levels of a tumor marker. Thus, doctors will consider tumor marker levels along with other information, for example from imaging tests.
Liver function tests (LFT)
These blood tests show if the liver is working properly. It is important to realize that the normal liver function can be affected by many conditions other than cancer. LFTs are also useful as an indicator of how well the liver works before, during and after treatment.
The only way to clearly diagnose cancer is to take a sample of tissue. This is called a biopsy. The tissue is viewed under a microscope. It can also show the origin and type of tumor that may be present in the liver. You may have a biopsy at the same time as an ultrasound or CT scan, usually with a thin needle. This is called a fine-needle aspiration (FNA) biopsy. The skin is numbed with a local anesthetic and a fine needle is inserted into the liver through the skin.
A biopsy is usually only done if other tests including blood tests and CT or MRI scans are not conclusive, ie, do not have obvious results. A biopsy always carries the risk that the tumor will spread along the needle track.
Following a liver biopsy, you may have to stay in hospital for a few hours or overnight. This is because the liver has a very rich blood supply and there is a risk of bleeding afterwards.