duct cancer (cholangiocarcinoma) is a type of cancer called adenocarcinomas, which starts in the lining of the bile duct. If cancer starts in the part of the bile ducts within the liver, it is known as intra-hepatic. If it starts in bile ducts outside the liver, it is known as extra-hepatic.
The cause of most bile duct cancers is unknown. There are a number of risk factors that can increase risk of developing bile duct cancer. Biliary ductal calculi occur in 20-50% of patients with cholangiocarcinoma;
People who have a chronic inflammatory bowel condition, known as ulcerative colitis, have an increased risk of developing this type of cancer. People who have primary sclerosing cholangitis, which is an inflammatory condition that affects the bile ducts, are also at an increased risk of developing bile duct cancer.
Abnormal bile ducts
People who are born with (congenital) abnormalities of the bile ducts, such as choledochal cysts, have a higher risk of developing bile duct cancer.
In Africa and Asia, a large number of bile duct cancers are thought to be caused by infection with a parasite known as the liver fluke. Parasitic diseases of the biliary tract with either Clonorchis sinensis or Opisthorchis viverrini infestation (C sinensis infestation is the most common cause worldwide.)
Although bile duct cancers can occur in younger people, more than two out of three occur in people over 65.
Diagnosis of Bile duct cancer. :
Cancer in the bile ducts block the flow of bile from the liver to the intestine (obstructive jaundice), which is progressive in nature and usually associated with pruritus ( itching) This causes bile to flow back into the blood and body tissues. Other symptoms include discomfort in the abdomen, loss of appetite, high temperature and weight loss.
The following tests are commonly used to diagnose bile duct cancer: Abdominal Ultrasound , CT scan , MRCP (Magnetic Resonance Cholangio Pancreatography) PET-CT (positron emission tomography) scan, ERCP (endoscopic retrograde cholangio-pancreatography) & Endoscopic ultrasound scan (EUS). It is difficult to confirm the diagnosis of bile duct cancer without surgery. However, cancer cell from bile duct can be retrieved (brush cytology ) during ERCP for cytological evaluation. Tumour marker as CA.19-9 is also helpful in certain cases.
The tumors are classified as extrahepatic tumors (87-92%) or intrahepatic tumors (8-13%).
Extrahepatic tumors are divided into proximal, middle, and distal ductal tumors. Tumors located at the confluence of the right and left hepatic ducts with the proximal common hepatic duct are called Klatskin tumors.
Types of Bile duct cancer
Treatment for bile duct cancer The treatment you have will depend on the position and size of the cancer, whether it has spread beyond the bile duct and your general health. In some situations, the aim of treatment will be to relieve symptoms.
The main treatment for bile duct cancer is surgery to remove the cancer. But this may involve a major operation and isn’t always possible. The major determinants of resectability are the following:The extent of tumor within the biliary tree,the amount of hepatic parenchyma involved,vascular invasion, hepatic lobar atrophy and metastatic disease.
Determination of resectability is most challenging in patients with Klatskin tumors. About half of patients with Klatskin tumors that are determined to be resectable preoperatively have unresectable disease intraoperatively
If the cancer is at early stage, then bile ducts containing the cancer and adjoin structures are removed , followed by anastomosis of remaining bile duct with intestine (biliary reconstruction) to establish bile flow from liver to intestine.
If the cancer has begun to spread into the liver, the affected part of the liver and the bile ducts are removed.
If the cancer is larger and has spread into nearby structures, then the bile ducts, part of the stomach, part of the small bowel (duodenum), the pancreas, gall bladder and the surrounding lymph nodes are all removed. This is known as whipple’s procedure which is a complicated and major operation
If it isn’t possible to remove the tumor, then an operation to create a bypass of the blocked part of the bile duct called hepatico jejunostomy is needed.
If a part of the small bowel called the duodenum is blocked, it can cause vomiting. This may be helped with an operation where the stomach is connects to part of small bowel (Gasrojejunostmy ) bypassing the duodenum.
Stent insertion :
If surgery is not at all possible then a stent (tube) is put in to the bile duct to allow bile to drain to intestine. . A stent may be put in using an ERCP or occasionally a PTC procedure. A stent usually needs to be replaced every 3-4 months to prevent it from becoming blocked. In certain situation permanent (metallic) stent may need to be deployed.
Oncological management : Radiotherapy and Chemotherapy and its combination chemoradiation is given in the inoperable cases and after surgery to control the residual tumour. But there is minimum role for oncological manipulation.