Bile ducts are a vital part of the biliary system. These tubes or ducts help to collect the bile from the liver and transport it to intestine. Bile is made in the liver and stored in the gall bladder until it is needed for digestion. Bile is the fluid that helps the intestines break down the fats in the food that we eat. Bile ducts carry the bile which is mainly present in the gall bladder through the cystic duct to reach the common bile duct. From the common bile duct, the bile flows into the smaller intestine. Cancers of the bile duct are called cholangiocarcinomas, and they may appear in or around the liver. Bile duct cancer in the area of the duct within the liver is called intra hepatic cancer. Perihilar or hilar bile duct cancers develop at the hilium, the place where the hepatic ducts are combined just before they leave the liver. These are also called Klastskin tumors. A malignant tumor in bile ducts that is on the outside of the liver is called extra hepatic bile duct cancer or a distal bile duct cancer. A majority of bile duct cancers are adenocarcinomas which start in the mucus glands that line the inner wall of the duct. It must be remembered that not all bile duct tumors are cancerous.
In a patient with a medical history of bile duct obstruction or a family history of bile duct cancer, doctors may order various bile duct cancer tests. Initially, when there is a suspicion of a tumor, blood tests may be ordered with tumor markers, bilirubin count, and so on. Tests of liver and gallbladder function can establish if these organs are working properly or if there is a tumor growing that affects their functioning. Imaging tests such as Magnetic Resonance Imaging scan can locate the tumor and its size, and help doctors determine the course of treatment to be followed. Computed tomography (CT) scan gives cross-sectional images of the abdomen using X-rays so that doctors can determine if the tumor is operable or not. A positron emission tomography (PET) scan uses radiolabeled tracers to get metabolic information about the tumor and the extent of lymph node metastases. Perhaps the simplest of all imaging tests is the ultrasound test, which creates an image of the bile ducts and the organs around by using sound waves.
Cholangiography uses a dye injected into the gall bladder to trace the movement of bile through the bile ducts. Cholangioscopy, on the other hand, uses a fiber optic endoscope inserted into the patient's body through the mouth to directly view the site. Variations of this technique with a SpyScope Catheter may be used in optically guided biopsies of the tumor and to fragment stones. Angiography may be done to verify the regular flow of blood in the vessels surround the bile ducts and the liver. Laprascopy or keyhole surgery is performed by surgeons to remove tiny tumors or relieve a block in the bile ducts. Chest X-ray may be done to check if the cancer has spread to the lungs.
Causes of bile duct cancers are not known, though several risk factors have been identified. These risk factors indicate the possibility of developing bile duct cancers in people with certain diseases like inflammatory bowel disease or ulcerative colitis. Among bile duct cancer causes in Asia and Africa, infection of a parasite called liver flukes is more common. Consuming raw fish that may be contaminated by the parasite increases the risk. Liver flukes may also be contracted when an individual is infected by any water borne disease, particularly in the tropics. There are several types of liver flukes and Clonorchis sinensis and Optisthorchis vevernini are the two associated with bile duct cancer. Sclerosing cholangitis, a liver and bile duct disease characterized by narrowing and scaring of bile ducts in the liver, may also result in cancer in the bile ducts. Cirrhosis of the liver also increases the risk of contracting bile duct cancer. Age is another important factor in bile duct cancer as it appears mostly in people over the age of 65. Congenital abnormalities in the formation of bile ducts and the appearance of cysts in the bile ducts may also lead to cancerous tumors. Although obesity may not be the direct cause of bile duct cancer, diseases caused by obesity such as stones in the gall bladder and in the bile duct may be a major cause. Injury to the bile duct caused by stones and blocking of the flow of bile by stones in the duct are also probable causes. Exposure to Thorium dioxide, a radioactive substance, other harmful chemicals, asbestos and use of tobacco are some of the other causes identified.
A tumor in the bile duct can block the flow of bile into the intestine and the bile that is accumulated in the ducts causes the skin to turn yellow. Itching is a common symptom that accompanies the jaundice-like appearance of the skin and the whites of the eyes. Bile duct cancer symptoms include loss of appetite, fever, and unexplained weight loss. Changes in stool and urine color are similar to jaundice symptoms, with clay colored stools and dark urine. Lack of appetite, nausea, and weight loss that cannot be explained are symptoms that appear for both bile duct cancer and jaundice. Since the bile ducts are deep within the body, any abnormalities or blocking of bile or tumors cannot be discovered during routine physical examinations. That is why bile duct tumors are called silent killers. Sometimes, abdominal pain caused by the accumulation of bile in the blocked ducts or an infection resulting from the block may indicate the presence of a tumor. Since the symptoms can be often confused with those of jaundice, gall bladder disease and liver problems, bile duct cancers are often not detected until the cancer has grown and starts to spread. As long as the cancer is localised within the bile ducts, it is operable and the person responds to treatment.
Surgery is the most commonly suggested option for bile duct cancer treatment if the tumor is contained within the bile duct and is operable. During the surgery part of the bile duct may be removed, and the remaining part is reconnected to allow the flow of bile. In case the cancer has spread to the liver, the liver or the diseased part of the liver may be removed. In cases of intrahepatic cancer where the liver is also affected, surgery to remove the entire liver and a liver transplant may be required. When the cancers cannot be removed, bypass procedures may be performed to circumvent the blockages in the gastrointestinal tract and the biliary tract to relieve the patient's jaundice symptoms. Those with blockages in the bile ducts may also be treated with a combination of laser and light activated chemotherapy. Also called photodynamic therapy, laser therapy is also used to relieve symptoms in case the tumors are not operable. A combination of chemo therapy and radiation therapy called chemoradiation is suggested after a surgery to remove bile duct cancer to prevent the risk of the cancer returning at the site.
In cases where there is a blockage preventing the free flow of bile, a stent may be introduced at the site, through an endoscope, to drain away the bile. This also helps relieve jaundice in patients whose tumors are inoperable. In those with such inoperable tumors, palliative therapy to relieve pain, itching and infection is needed. Among clinical trials being carried out to study the efficacy of various methods of treatment for bile duct cancer, the use of new chemotherapy drugs and the combination of photodynamic therapy and stents hold promise. Clinical trials are also underway to study the efficacy of drugs that inhibit new blood vessel growth in tumors so that the cancer does not grow. Proteins that help cancer cells to grow are targeted by drugs so that the growth of these tumors can be contained and trials of these drugs hold promise for bile duct cancer patients.
Complementary and alternative therapies including herbal supplements, naturopathic medicines, and nutrition therapies may be suggested to relieve symptoms such as itching and nausea. Support groups offer the spiritual and psychological support that is needed when a patient undergoes treatments like chemotherapy that have unpleasant side effects. Nutrition can be an important factor in the recovery because the treatment places greater demand for nutrients. More calories may be needed to compensate for the lack of vitality caused by rapid weight loss.