The National Cancer Institute estimates that nearly 40% of Americans will be diagnosed with cancer at some point during their life. Breast cancer, lung cancer, prostate cancer, and colorectal cancer are the most commonly diagnosed types, but there are unfortunately many others as well. One example of a less common type is bile duct cancer; though only about 8000 new cases surface each year in the United States, the difficulty in diagnosing the disease could mean that the actual number of cases is significantly higher.
What to Know About Bile Duct Cancer
Bile duct cancer (technically referred to as cholangiocarcinoma), as the name implies, is a form of cancer that begins in the bile ducts, a network of thin tubes that carry bile from the liver to the small intestine. Bile is important in the digestive process because it helps the body break down lipids in the food we eat. Any form of cancer is bad, but bile duct cancer can be particularly challenging because of how it can lead to a harmful blockage of either the hepatic duct or the common bile duct (collectively known as the biliary system).
Under normal circumstances, the liver produces bile, a greenish-yellow fluid that is composed of water, bile salts, cholesterol, and bilirubin. Secreted bile gathers in the hepatic ducts within the liver before being temporarily stored in the gallbladder between meals. When partially digested food from the stomach (in a form known as chyme) enters the small intestine through the duodenum, bile and other digestive enzymes from the pancreas begin the process of breaking down the food into components that can be absorbed into the bloodstream.
As with cancer in general, sometimes abnormal cellular growth within the biliary system can begin to grow out of control. This kind of growth can start in any of the different bile ducts, but there are a few main areas where cancer is more likely to develop. And the type of bile duct cancer is dependent on which part of the bile duct a growth first appears:
- Intrahepatic bile duct cancer: This subtype of bile duct cancer starts in the small ducts that reside within the actual liver, and because of this the cancer cells are sometimes confused with liver cancer. These ducts are spread all over the liver and are used to gather secreted bile and carry it to the gallbladder.
- Perihilar bile duct cancer: This type is also known as extrahepatic bile duct cancer because it starts just outside the liver where the right and left hepatic ducts meet. When the abnormal growth gains sufficient, it is usually referred to as a Klatskin tumor after the American physician first described it in the 1960s.
- Distal bile duct cancer: Distal bile duct cancer develops in the distal portion of the bile duct, nearest to the small intestine; it is in this area where the ducts from the liver and gallbladder join to form the common bile duct.
Symptoms of Bile Duct Cancer
Like numerous other forms of cancer, there are generally no symptoms of bile duct cancer in the early stages. In some cases, though, symptoms can present early on if the growth is substantial enough to block the bile ducts. Eventually, as the growth gets larger and becomes a tumor, there are a variety of symptoms that may be experienced:
- Jaundice: Jaundice is one of the most common and noticeable symptoms because it involves the yellowing of the skin and the whites of the eyes. This can occur when an abnormal growth obstructs the bile duct and prevents bile from flowing into the small intestine. In these circumstances, bilirubin, a yellow pigment and the only part of bile that can get through, builds up in the bloodstream. It’s important to note that jaundice is also often an indicator of liver disease, cirrhosis, or an infection by a particular type of parasites called liver fluke.
- Abdominal pain: Persistent abdominal pain, particularly in the upper right side of the abdomen, may occur as the tumor grows and presses against nearby structures. This pain can range from mild to severe and may be constant or intermittent.
- Weight loss: Many patients with bile duct cancer (or other forms of cancer) can also have unexplained weight loss as a result of cancer-related metabolic changes and reduced appetite.
- Itchy skin: A bile duct obstruction can additionally lead to an accumulation of bile salts in the bloodstream that can cause an itching feeling on the hands and feet.
- Stool color: The absence of bile in the small intestine can lead to changes in stool color, making it pale or clay-colored. The urine may also become darker as bilirubin is excreted through the kidneys.
- Fatigue: Chronic fatigue is a common symptom in individuals with bile duct cancer. It can be a result of the cancer itself or a side effect of treatments.
How is Bile Duct Cancer Diagnosed?
Since the symptoms of bile duct cancer are late to present and are associated with several other medical conditions as well, a more thorough process is required for diagnosis. This usually involves a medical examination and review of family medical history before various tests can be performed. Here are some standard tests used to arrive at a bile duct cancer diagnosis:
- Blood test: Blood tests are typically ordered to assess liver function and identify any abnormalities. These tests can include liver function tests, bilirubin levels, and tumor markers, although tumor markers for bile duct cancer are not as specific as those for some other cancers.
- Imaging tests: Standard tests like a CT scan or MRI are often chosen first because they are relatively easy to perform and work well. A doctor may also use endoscopic retrograde cholangiopancreatography (ERCP), a diagnostic and therapeutic procedure that involves passing the flexible tube of an endoscope through the mouth and into the small intestine to inject contrast dye into the bile ducts; the contrast dye then helps visualization during X-rays. If ERCP doesn’t work for some reason, the doctor can also use percutaneous transhepatic cholangiography (PTC), a more invasive version of ERCP that requires puncturing the liver to inject the contrast medium.
- Biopsy: Often the definitive method for diagnosing bile duct cancer is a biopsy of tissue from the abnormal growth. The tissue sample is usually gathered via endoscope, and then the sample is evaluated at a lab.
Bile Duct Cancer Treatment Options
Any treatment plan for bile duct cancer is naturally dependent on the location of the tumor in the biliary system and how far the disease has progressed. The patient’s overall health and medical history are also relevant factors since not every person is a good candidate for surgery, for instance. Below are some common treatment options for bile duct cancer:
- Surgery: Surgical removal of the tumor is the preferred treatment whenever possible. This can involve removing a portion of the bile duct, the affected liver lobe, and sometimes nearby lymph nodes. In rare cases a liver transplant may be necessary.
- Chemotherapy: Chemotherapy is the use of medication to treat cancer by preventing the cancer cells from growing and dividing. This is also often used in combination with surgery to attempt to shrink the tumor before it is removed.
- Radiation therapy: This method uses targeted high energy radiation to kill cancer cells in a particular location. It may also be used in conjunction with other methods.
- Stent: In cases where the cancer is too advanced to effectively treat, surgery may be used to implant a stent, a small tube that bypasses the tumor and allows bile to flow normally.
Contact a Gastroenterologist
The good news is that bile duct cancer is rare. And if you have been experiencing any of the symptoms noted above, there is probably another explanation. Yet gastrointestinal symptoms and diseases have a way of negatively affecting quality of life even if they’re not considered “serious.” At Cary Gastro, we are passionate about digestive health care and helping patients feel better and have peace of mind. If you have been having symptoms you’re unsure about, contact us today to request an appointment.