How Does My Doctor Know I Have Bile Duct Cancer?
If you’re having symptoms similar to those of bile duct cancer, your doctor will want to know why. You should undergo a complete medical evaluation. Your doctor is likely to ask you questions about your:
Medical history, such as a history of bile duct problems
Lifestyle habits, such as smoking cigarettes
Exposure to other risk factors, such as working with industrial chemicals or travel to East Asia or the Middle East, where an infection with a certain type of parasite called a fluke is common
In addition to asking you questions, your doctor will also perform a physical exam, which includes an exam of your abdomen. The doctor will likely look for signs of bile duct cancer, such as yellow skin or eyes. You may need tests to know for sure whether or not you have cancer. The results of these tests may be enough to rule out cancer. Or the results may require more tests.
To tell if you have cancer, your doctor will need to remove cells by taking a piece of the tumor from your bile duct. This is called a biopsy. A doctor called a pathologist looks at the sample under a microscope. This doctor specializes in looking for cancer cells to confirm a diagnosis.
You may have one or more of the following tests to help confirm your diagnosis.
Liver enzymes and liver function tests
Liver function tests are blood tests that check how well your liver is working or whether it has been injured. Bilirubin, prothrombin time (international normalized ration or INR), and albumin are the best liver function tests. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), and gamma-glutamyl transpeptidase (GST) are not liver function tests. These are tests of liver enzymes and are indicated for liver inflammation, irritation, or bile duct blockage, depending on the pattern. Bile duct cancer can affect liver function tests. The doctor takes a small sample of your blood and checks its level of bilirubin to see whether there is an obstruction in your bile duct system. Another test looks for a substance called alkaline phosphatase. Damaged bile duct cells release this. If you have high levels of AP and GGT, it may mean that something is blocking a bile duct. By itself, the test cannot show if the obstruction is due to cancer or something else.
This is another type of blood test. This one looks for increases in certain substances called tumor markers. Some cancers make these substances. If you have bile duct cancer, two markers may be increased: carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9). If your tumor markers are high, it may suggest that cancer or another disease is present. However, a normal level of tumor markers does not always rule out the presence of cancer. Your doctor may repeat this test during your treatment to check for signs of cancer.
This test uses sound waves to look for problems in the bile duct. The sound waves bounce off body parts and send back signals, like sonar on a submarine. A computer then receives the signals and creates an image of the inside of the body. This test is very helpful in detecting masses inside the body and learning more about them. If a mass is a fluid-filled sac, called a cyst, it’s probably not cancer. If it’s a solid tumor, it is more likely to be cancer. Ultrasound can show enlarged bile ducts and reliably find masses that are larger than 1 centimeter (cm), which raises the suspicion for cancer.
Endoscopic retrograde cholangiopancreatography (ERCP)
This test is one of the most useful ways to find bile duct cancers that are closer to the pancreas. During this test, the doctor passes a flexible tube called an endoscope down your throat, through your stomach, and into your small intestine. The doctor then passes a smaller scope through the endoscope to inject dye into your common bile duct. The dye highlights any abnormalities on X-rays. Your doctor can also use this test to obtain a biopsy, which is a sample of tissue removed to be examined under a microscope. For the biopsy, the doctor collects cells with a small brush and biopsy forceps. During an ERCP, the doctor may also insert small, expandable tubes, called stents, to reopen a duct blocked by cancer.
Endoscopic or laparoscopic ultrasound
Your doctor may also use this new kind of ultrasound called endoscopic or laparoscopic ultrasound. These tests use a thin, lighted tube with a viewing device attached called an endoscope. Your doctor may insert the endoscope through your mouth and into your stomach near the bile duct area. Or you may have surgery to make a small cut in your side so that your doctor can see inside your abdomen using a tool called a laparoscope. Both procedures allow the doctor to get closer to the bile ducts to use ultrasound, which allows for more detailed images. These methods may be used to help in the removal of tissue for a biopsy to confirm the diagnosis. Your doctor can also use this test to see more clearly whether the cancer has spread and, if so, how far.
Percutaneous transhepatic cholangiography (PTC)
The doctor may do PTC when ERCP is not able to reach the site of obstruction caused by cancer. Although it’s a more invasive procedure, PTC gives the best picture of the bile ducts. It is also very useful for bile duct cancers that are closer to or inside your liver. It can show the exact location and size of the tumor. This test can also help to see if the tumor can be removed by surgery. The doctor uses a needle placed through the skin over your liver to inject dye into your bile duct system inside your liver. Then X-rays can show any abnormalities or blockages in your bile ducts. The doctor can also take a small sample of tissue called a biopsy during this test. If the doctor sees a blockage, he or she may place a special type of stent to bypass the bile blockage and allow the bile to temporarily flow into a bile bag outside of the body. This is called percutaneous transhepatic bile drainage (PTBD).