Bile Duct Cancer: Types, Causes, Symptoms, Diagnosis, Treatment, Complications
About Bile Duct
Bile duct cancer is also known as adenocarcinoma growing in the bile duct itself. Bile ducts are basically a group of thin tiny tubes which carries a form of fluid called bile from the liver and gallbladder to the small intestine. The bile helps in the digestion of the food.
The different parts of the bile duct system are named differently. In the liver, they are known as ductules which carry bile from the liver, and form groups which are called ducts. Further, these ducts combine together to form larger left and right ducts. All these ducts within the liver are known as intrahepatic bile ducts.
The hepatic ducts present at the left and right side makes an exit from the liver to create the common hepatic ducts at a particular location which is called hilum. The gallbladder is mainly an organ which stores the bile duct. The common hepatic duct joins the gallbladder through a duct which is called the cystic duct. This combination is called the common bile duct which travels through certain parts of the pancreas before it joins the pancreatic duct that empties in the first section of the pancreas called the duodenum. Bile duct cancer can occur in any of these regions of the bile duct.
Types of Bile Duct Cancer
Bile duct cancer can be broadly classified into two different types. They are extrahepatic bile duct cancer and intrahepatic bile duct cancer.
Extrahepatic Bile Duct Cancer:
Extrahepatic bile duct cancer grows from the outer layer of the liver and gets carried to the bile duct which is present in the liver. Intake of too much alcohol, fatty liver, obesity, hepatitis C, and cirrhosis of liver can lead to the occurrence of extrahepatic bile duct cancer. It has two categories based on the location of their origin. They are:
- Bile Duct Cancer of the Perihilar Region: This is the most common bile duct cancer that begins in just the outer part of the liver, the area where the right and the left hepatic ducts connect each other. Also known as Hilar Cancer or Klatskin Tumours, the disease, most often than not, starts growing in the perihilar region in the bile duct.
- Bile Duct Cancer of the Distal Region: This form grows within the bile ducts just under the perihilar area and close to the small intestine. It is a rare type that confuses the surgeons to identify if the cancer has originated in pancreas or bile duct.
Intrahepatic Bile Duct Cancers:
Intrahepatic bile duct cancer originates in the inner part of the liver where numerous tiny bile ducts connect to constitute the right and the left hepatic bile duct. Only 20% of malignant cell begins in the intrahepatic region and sometimes confuses the doctors with the hepatocellular cancer that grows in the liver cells itself.
Symptoms for Bile Duct Cancer
The excretion of the bile is haltered when the duct is blocked. However, it is not necessary that the bile is blocked due to the cancer cells. It can be blocked for other reasons like gallbladder stone or a scar tissue.
Jaundice is a very common and primary symptom for bile duct cancer patients. It creates a high count of bilirubin in the blood causing the skin and the white of the eyes to turn yellow. Bilirubin also changes the color of urine to dark in color and makes the bowel passage pale and disturbed.
It must be kept in mind that jaundice is not only a symptom for cancer but also many other diseases. Therefore, the doctor must perform several other tests too finally diagnose cancer.
Other Symptoms of Bile Duct Cancer are:
- Weight loss without any prominent cause
- Repeated fever
- Skin irritations caused due to the bile being piled up
- Appetite loss
- Abdominal pain might not be experienced at an early stage. Only if the cancer cells are spread the pain shows up.
Risk Factors for Bile Duct Cancer
60% of the bile duct cancer victims are of the age of 65 years and above. Bile duct cancer is not a very commonly diagnosed disease among kids or young people.
Being overweight and obesity increase the chances of developing bile duct cancer cells.
A family history of bile duct cancer increases the risk of bile duct cancer in a patient. Even after that, the chances are not too high because this disease is a rare one.
Lifestyle as a Risk Factor for Bile Duct Cancer:
Excessive alcohol intake might cause cirrhosis of the liver. This further increases the risk of bile duct cancer. Smoking also might risk the cause of bile duct cancer. Exposing oneself to certain chemicals like nitrosamines, dioxins, asbestos, polychlorinated biphenyls (PCBs), radon and thorotrast might increase the risk factor of developing cancer cells in the bile duct.
Other Conditions as a Risk Factor for Bile Duct Cancer:
Some conditions like ulcerative colitis, bile duct stones and primary sclerosing cholangitis cause inflammation of bile ducts and scarring which might increase the risk factor for bile duct cancer.
Diseases that occur in the liver or bile duct can be proven to be dangerous to give the cancerous cells a chance to develop. Any disease in these areas which are not treated for a long period increases the risk factor.
Certain parasitic infections are the key to a disease called as liver fluke. This affects the bile directly and can cause cancer.
Diagnosis of Bile Duct Cancer
When jaundice shows up, the doctor suggests several examinations which indicate the cancer. Even the history has a vital role here because substance abuse like alcohol and drugs can be a cause of bile duct cancer. Additionally, loss of appetite, weight loss, loss of energy, bleeding etc., are the symptoms. Tenderness in the right upper quadrant of the abdomen is also detected during the physical examination.
Blood tests are done to check the liver function. The doctor confirms the diagnosis with the biopsy report obtained from the tissue sample. Followed with this, USG, MRI and CT scan are done to determine the structure of the gallbladder, bile ducts, and the size and location of the tumor. Endoscopic Retrograde Cholangiopancreatography (ERCP) is performed with a fiberoptic camera to test the bile duct when it gets into the duodenum.
The risk of bile duct cancer depends on its stage ranging from 0 to 4. Stage 0 of bile duct cancer indicates no tumor, while stage 1 of bile duct cancer suggests local tumor which has not yet spread to other areas. Stage 4 of bile duct cancer is a serious condition wherein there is a significant growth in the tumor locally as well as in the lymph nodes and in the other areas. The answer of the critical stage often lies in surgery. If the surgery is successful, the survival rate is high.
Treatment for Bile Duct Cancer
A bile duct cancer patient can be treated in several ways. The three standard types are:
- The bile duct is being removed partially if the tumor is within the bile duct only.
- A part of the liver where cancer cells are found is removed, also known as partial hepatectomy.
- Whipple procedure where a part of the stomach and small intestine, top area of the pancreas and the bile duct is removed.
In radiation therapy for bile duct cancer, high radiation or x-rays are used to kill the cancer cells or stop them from growing and spreading.
Chemotherapy for Bile Duct Cancer:
In Chemotherapy for bile duct cancer, the drug is directly injected into the vein or through pills. When the drug is injected it mixes with the blood and treats the cancer cells all over the body. Chemotherapy arrests the growth of cells and stops from spreading to other parts.
A systematic chemotherapy is a treatment offered to the metastatic patient or for patients whose bile duct cancer is recurrent.
Stent insertion is a surgery that widens and removes the blocks in the bile duct. It reduces the abdominal pain, itchiness and yellowish skin. A hollow tube i.e., a stent is used to keep the duct open. The tube or the stent is inserted through the throat called endoscopy or an incision. Sometimes, the stent also gets blocked which suggests a replacement of the stent.
Extensive researches and clinical trials are carried on the patients throughout the world to discover better treatments. Human body reacts and responds to different treatments in different ways. However, doctors provide strict instructions to follow-up during cancer treatment which must not be ignored at any cost.
Complications in Bile Duct Cancer
The blockage in the bile duct can contribute to infection of the bile system. The cancer might destroy the liver cells that might lead to scarring and Cirrhosis of liver and sclerosing cholangitis. These are eminent risk signals in bile duct cancer patients.
Special care must be taken to adhere to the treatment advised. It is very essential to not ignore the symptoms of bile duct cancer if observed so that the condition can be diagnosed at the earliest. The earlier the diagnosis, the better is the treatment outcome and the survival rate.