What tests are carried out to diagnose Gallbladder cancers?
This section lists common tests that may be performed and it is not necessary for all the tests to be performed for a patient. Your doctor will select the tests that will assist him /her to have the maximum information about the tumor/ disease.
Tests of liver and gallbladder function: The doctor may order lab tests to find out how much bilirubin is in the blood. Bilirubin is the chemical that causes jaundice. Problems in the bile duct, gallbladder, or liver may cause too much bilirubin to remain in the blood. A high bilirubin count tells the doctor that there may be problems with the bile duct, gallbladder, or liver.
The doctor may also order tests for other substances in your blood, such as albumin, alkaline phosphatase, AST, ALT, and GGT. These are sometimes called liver enzymes or liver function tests. They can also give an indication of bile duct, gallbladder, or liver disease. Higher levels of these substances may point to blockage of the bile duct, but they cannot show if it is due to cancer or some other reason.
Tumor markers: Tumor markers are substances made by cancer cells that can sometimes be found in the blood. People with gallbladder cancer may have high blood levels of the carcinoembryonic antigen (CEA) and CA 19-9 tumor markers. Usually the blood levels of these markers are high only when the cancer is in an advanced stage. These markers are not specific for gallbladder cancer — that is, high levels can also be caused by other cancers or even some other health conditions.
Ultrasound (US or ultrasonography) is often the first imaging test done in people who have symptoms such as jaundice or pain in the right upper part of their abdomen. On the basis of results of this ultrasound the doctor may decide for the next best investigation.
Computerised tomography (CT) scan
A CT scan is a type of x-ray that gives a picture of organs and other structures (including any tumours) in your body. It is used to see more details of a cancer and its relation to the surrounding organs in your body. It also gives information related to cancer spread into the lymph nodes, liver or lungs.
Magnetic resonance imaging (MRI)
This test is like a CT scan, but it uses magnetism instead of x-rays to build up pictures of the organs in your abdomen. Like a CT scan, MRI is painless and the magnetism is harmless. MRI scan may be used to see the extent of blockage of bile duct and in case the patient is allergic to contrast dye injection used for CT scans. MRI scans provide a great deal of detail and can be very helpful in looking at the gallbladder, bile ducts and nearby organs. Sometimes they can help tell a benign tumor from a malignant one.
Endoscopic ultrasound scan (EUS)
This involves a special endoscope equipped with an ultrasound probe and a small needle at the end. The scope is placed through the mouth into the oesophagus (food pipe) and the first portion of the small intestine for more detailed information about the local spread of the tumor. If there is a tumor, ultrasound may help the doctor tell if and how far it has invaded the gallbladder wall, which helps in planning for surgery. Ultrasound may be able to show if nearby lymph nodes are enlarged, which may be a sign that cancer has reached them. It may also be used to guide a needle into a suspicious node so that cells can be removed (biopsied) and viewed under a microscope.
Positron emission tomography (PET) scan
This test is combined with a CT scan by injecting a radioactive material in the body to highlight all areas where the tumor has or can spread. This test may be used to build up more information after an MRI or CT scan. PET-CT scan is not necessary for all patients. Your doctor will decide if you need to undergo this scan.
Imaging tests can suggest that a bile duct cancer is likely to be present, but in many cases a sample of bile duct cells or tissue is removed (biopsied) and looked at under a microscope to be sure of the diagnosis.
But when gallbladder cancer is likely, a biopsy may not always be done before surgery to remove the tumor. Doctors are often concerned that sticking a needle into the tumor or otherwise disturbing it without completely removing it might allow cancer cells to spread to other areas.
If imaging tests (ultrasound, CT or MRI scans, cholangiography, etc.) suggest there is a tumor in the gallbladder and there are no obvious signs of distant spread, the doctor may decide to proceed directly to surgery and to treat it as a gallbladder cancer. (See the section,”Surgery.”) In these cases, the gallbladder tissue is looked at under a microscope after the gallbladder is removed.
In other cases, a doctor may feel that a biopsy of a suspicious area in the gallbladder is the best approach to know for certain that it is gallbladder cancer. For example, imaging tests may show that a tumor has spread or grown too large to be completely removed by surgery. Unfortunately, many gallbladder cancers are not removable by the time they are first found.