Bile duct cancer is a rare type of cancer that starts in the bile duct. Bile ducts are slender tubes that connect the liver, gallbladder and small intestine. The primary function of the bile duct is to allow the bile juice to flow from the liver to the small intestine, where it aids fat digestion and absorption.
Bile duct cancers are aggressive and are often detected in later stages. However, in a few cases, early detection is possible.
Early detection and accurate diagnosis are important for bile duct cancers to be treated with positive clinical outcomes.
Based on the location of tumour formation, the bile duct cancers are classified into three types:
1. Intrahepatic Bile Duct Cancers: Intrahepatic bile duct cancers form in the smaller bile duct branches within the liver. They are often confused with hepatocellular carcinoma, which forms in liver cells. 1 in ten bile duct cancers is reported to be intrahepatic.
2. Perihilar Bile Duct Cancers: Also called Klatskin tumours, perihilar bile duct cancers form at the hilum region of the liver. These are the most common types of bile duct cancers and make up to around 6 to 7 of every ten bile duct cancers.
3. Distal Bile Duct Cancers: These cancers form in the further lower region of the bile duct, closer to the small intestine. These cancers make up to 2 to 3 out of every ten bile duct cancers. These cancers are grouped with perihilar bile duct cancers as extrahepatic bile duct cancers.
Bile duct cancers are most often detected in later stages, once the signs and symptoms start showing. However, in few cases, early diagnosis is possible. Here are some of the symptoms that are associated with bile duct cancer:
- Itching sensation in the skin
- Abdominal pain
- Light-coloured stools
- Dark-coloured urine
- Loss of appetite
- Weight loss
- Nausea and vomiting
Bile duct cancers are rare. However, there are certain factors that can increase one’s risk of developing bile duct cancer.
- Long-standing Inflammation: Long-standing inflammation is the biggest risk factor that is associated with bile duct cancers. Following inflammations, when chronic, may increase the risk of bile duct cancer:
- Sclerosing cholangitis causes inflammation by scarring the bile ducts and sometimes destroying them.
- Ulcerative colitis increases bile duct cancer risk through ulcer formation in the rectum lining and colon.
- Bile duct stones, if unaddressed, may lead to bile duct cancer.
- Cirrhosis, which is most often caused by alcohol consumption and infections, such as hepatitis C and B, leads to progressive scarring of the liver and may increase the risk of bile duct cancer.
- Age: The risk of developing bile duct cancer increases with age. Nearly 60% of the individuals who develop bile duct cancer are over the age of 65.
- Liver Fluke Infection: This is a parasitic infection that occurs with the consumption of undercooked freshwater fish.
Upon consumption, this parasite, liver fluke, inhabits the bile ducts and may lead to bile duct cancer, if untreated. The cancer-causing species of liver fluke are commonly found in the Southeast Asia region.
Other risk factors include having a family history of bile duct cancer, smoking and underlying medical conditions, such as diabetes and pancreatitis.
Bile duct cancer is a relatively challenging medical condition to diagnose. If bile duct cancer is suspected, the following tests may be recommended to get a conclusive diagnosis:
a. Blood Tests: The cancer cells release certain chemical components, known as tumour markers, which can be detected through blood tests. Therefore, blood tests are recommended if bile duct cancer is suspected.
However, it is important to note that these markers are released in other conditions too, and the presence of these markers in the reports does not necessarily mean that it is bile duct cancer and vice versa.
b. Imaging Tests or Scans: Scans such as ultrasound, computerised tomography (CT) and magnetic resonance imaging (MRI) are conducted to determine the exact location, shape and size of the tumour. The results from these scans play a significant role in disease staging as well.
c. Endoscopic Retrograde Cholangiopancreatography (ERCP): This is a unique imaging procedure that combines X-ray and the use of an endoscope. During the procedure, a special liquid is injected to see the bile duct region more clearly during the X-ray scan. The X-ray scanner guides the endoscopy (through the throat), which helps in detecting blockages, the presence of tumours or any other abnormalities.
d. Spyglass: As an advanced form of ERCP test, Spyglass allows the specialist to pass a specialised endoscope into the bile duct to check if there are any abnormalities. Spyglass also allows the technician to precisely collect samples for biopsy.
e. Biopsy: A biopsy is performed to confirm the diagnosis of bile duct cancer. During the procedure, a small sample of the bile duct tissue is excised and examined under the microscope for the presence of cancer cells. In a few cases, samples of the surrounding lymph nodes may also be taken in order to check whether cancer has metastasised to the lymphatic system.
The treatment plans for bile duct cancers are devised based on multiple factors such as the type of the tumour, stage of the disease, size, age and overall condition of the patient. In stage 1 and stage 2 cases, the tumour may be surgically removed along with some portions of the liver and gallbladder.
In advanced-stage cancers, the treatment plan will be made based on how many lymph nodes and organs have been affected. For a few cases, radiotherapy, chemotherapy and surgery are performed to relieve symptoms and help patients have a better quality of life.
a. Surgery: Surgery is considered to be the main line of treatment for bile duct cancers. Depending on the stage and the extent of cancer, the surgery may involve the removal of the following:
- The part of the bile duct that is affected by cancer
- The gallbladder
- Surrounding lymph nodes
- Part of the liver
Due to the aggressive nature of this disease, less than 1/3rd of patients are eligible for surgery. Usually, this surgery is followed by the reconstruction of the bile duct so that the bile can still flow into the intestine.
b. Unblocking the Bile Duct: If the tumour is blocking the bile duct, the doctor may recommend a procedure to unblock the duct. This procedure may help in addressing the disease symptoms such as jaundice, itchy skin and abdominal pain.
The bile duct is unblocked using a small metal or plastic tube called a stent. This stent is used to widen the bile duct and restore the bile flow. It can be inserted through endoscopic retrograde cholangiopancreatography (ERCP).
A variation of the percutaneous transhepatic cholangiography (PTC) procedure is also used for stent insertion. During this procedure, small incisions are made in the stomach for inserting the stent and restoring the bile flow.
c. Radiotherapy: Radiotherapy and chemotherapy may be administered as adjuvant therapies after the surgery in order to reduce the risk of relapse. This treatment is also used to relieve the symptoms and delay the progression of the disease in bile duct cancer patients.
d. Chemotherapy: Just like radiation therapy, chemotherapy may also be administered as adjuvant therapy to reduce the recurrence risk, or as palliative therapy to delay the disease progression and relieve the symptoms associated with the disease.
e. Photodynamic Therapy (PDT): Photodynamic therapy is a unique approach to shrink the tumour in bile duct cancer patients. This procedure helps control, but not cure, the symptoms associated with the disease. It makes the cancerous cells more sensitive to light, and later, the laser is passed through an endoscope in order to shrink the tumour.
This treatment helps in alleviating the symptoms associated with the disease and improving the quality of life among the patients.
Frequently Asked Questions
1. What questions should I ask my oncologist if I am diagnosed with bile duct cancer?
Following are the important questions that you must ask your oncologist if you are diagnosed with bile duct cancer:
- What type and stage of bile duct cancer do I have?
- What treatments will I be having?
- What should I do to be ready for treatment?
- How long will treatment last? What will it be like? Where will it be done?
- What side effects can I expect?
- Are there supportive care services I can take advantage of?
- How will treatment affect my daily activities?
- What would my options be if the treatment doesn’t work or if my cancer comes back?
- What type of follow-up will I need after my treatment?
2. Are bile duct cancers treatable?
Bile duct cancers are treatable. However, early detection and accurate diagnosis are important for positive clinical outcomes.
Treatment planning is made based on the type of tumour, the stage of the disease, the patient’s age and the overall condition of the patient. The treatment plan and the prognosis will be discussed with the patient so that they will know what to expect from the treatment.
3. Is bile duct cancer the same as liver cancer?
Bile duct cancers are often misdiagnosed as liver cancers. Bile ducts are thin tubes that form a network and connect the liver, gallbladder and small intestine.
Bile duct cancers are those that originate in these tubes, whereas liver cancers begin in the liver cells.
4. Does a patient with bile stone develop bile duct cancer?
Not all patients who have bile stones develop bile duct cancer. However, it is important to know that the bile stones can cause inflammation which, if ignored, may lead to an increased risk of developing bile duct cancer.
5. Does alcohol consumption cause bile duct cancer?
Increased alcohol consumption causes cirrhosis, which is one of the risk factors for intrahepatic bile duct cancer. So yes, alcohol consumption is one of the risk factors for bile duct cancer.