Although bile duct cancer may not necessarily hold the same significance as is attached to many other cancers- like cancer of the eye or lungs, or the ever-invasive cancers of the male and female reproductive organs, for instance- that does not mean that bile duct cancer is not equally damaging and painful, or that the bile duct is a structure to be taken lightly. Bile duct cancer, as the name suggests, affects the bile ducts of the body; these ducts are part of an entire network which aids in the transport of bile to and from various organs of the body. Essentially, this transport is an all-important part of digestion, for when when a person eats, bile is released from the gall bladder to the small intestine, where it helps break down fatty foods. These disintegrated foods, of course, will eventually be used as energy, or will be released through stool.

Causes of Bile Duct Cancer

Despite being rare in comparison to other forms of cancers, bile duct cancer nonetheless effects about 2,000 people a year in the United States alone. While there is no exact cause of bile duct cancer, per se, statistics show that the majority of patients are over the age of 65. This implies, then, that the disease is mainly acquired in a later stage of life. Another factor which has shown a considerable link to bile duct cancer is liver disease, although other sources of bile duct inflammation are equally high risk factors. While the abundance of liver-fluke infestations in certain countries has been proven to widely cause inflammation, and therefore, a very high risk of bile duct cancer development, this is usually limited to certain countries of the Eastern world, primarily in Southeast Asia.

In the U.S., however, a common onset of bile duct inflammation includes the formation of bile duct stones or gallstones. People that are obese, or that have high cholesterol, diabetes, or certain blood disorders are all more likely to have such stone formations. Smoking, pancreatitis, and exposure to asbestos and radioactive chemicals also increase a person's risk of bile duct cancer development, although more extensive research is needed to confirmed these. Regardless of whether or not a person is at risk of tumor growth in the bile duct, there are certainly preventative measures which can be taken to assure that the risk is as minimal as can be.

Types of Bile Duct Cancer

In general terms, bile duct cancer- or cholangiocarcinoma- is when a malignant adenocarcinoma cell mass forms anywhere within the bile duct system. Almost all bile duct cancers are considered adenocarcinomas, which is a term used to describe a glandular tissue (a tissue with the ability to secrete) that has turned cancerous.

Depending on where the cancer is precisely located in the bile duct system, one of three different names will be assigned to the tumor: intrahepatic bile duct cancer forms in any of the bile duct branches located within the liver; perihilar bile duct cancer forms at the hilum, which is the location where the right, left, and common hepatic ducts of the liver join together in leaving the liver; and lastly, an extrahepatic bile duct cancer, or distal bile duct cancer, forms further down the bile duct tube, closer to the small intestine. A multi-focal cancer refers to cancers in multiple parts of the bile duct network.

Symptoms of Bile Duct Cancer

Regardless of the type of bile duct cancer which affects a person, symptoms are typically the same. Since the bile duct is located so deep within the body, most of these symptoms will be characteristic of a cancer which has already progressed and caused enough harm to actually show symptoms. The most common of these will undoubtedly be jaundice, which is a yellow discoloration of the skin and whites of the eyes due to bile buildup in the bloodstream. In almost all instances, this buildup is caused by a tumor blockage in one of the main bile ducts, and roughly 90% of bile duct cancer patients will show this symptom before getting diagnosed. Additionally, a person's skin might itch (known as pruritus), and because the body is trying to release bile through other means, urine may turn to a darker color while stool turns to a lighter color. Abdominal pain, poor appetite and weight loss are also fairly common symptoms of bile duct cancer.  

Screening and Diagnosis of Bile Duct Cancer

Like mentioned above, because symptoms of bile duct cancer usually arrive only after a tumor mass has developed, it is extremely difficult to screen people for bile duct cancer before the tumor materializes and does damage. As a result, most patients are left to battle the disease without any prior warning earlier on in life, unless, of course, a medical family tree has shown previous biliary cancers. Since symptoms of bile duct cancer could also be associated with a variety of other conditions, such as liver disease, diagnostic tests are the only way to confidently assure that bile duct cancer is indeed present. A physical exam will usually be the initial step, to see if potential tumor masses are affecting organs and tissues in the abdominal areas surrounding the bile duct. Abnormalities in the form of lumps, tenderness, jaundice, or signs of fluid build-up will all be carefully looked for. Next, a variety of blood tests, imaging tests (such as ultrasounds, CT / MRI/ PET scans), cholangiography tests, or biopic exams will be performed to further diagnosis the cancer, if necessary, and to appropriately apply a stage to the cancer. Cancer staging is an essential part of cancer diagnosis as it assigns a severity to the tumor, which aids in choosing the best possible treatment.

Prognosis of Bile Duct Cancer

Even though a stage is assigned to a bile duct cancer based on the location of a tumor and the extent of its spreading, essentially, every cancer case is unique, and so a prognosis should not let go hope of a full recovery. Generally, a bile duct cancer prognosis takes into account many different factors, including the possibility that complications are likely to occur during the treatment period, and the rates of recovery, survival, and death which have been gathered from past bile duct cancer cases. Something to remember is that bile duct cancer is relatively slow-spreading, so even when diagnosed and given a general outlook, fast treatment often produces fast results, which can significantly prolong life expectancy.  

For bile duct cancer patients, the five-year survival rates can be as low as 2 percent or as high as 30 percent. This number relates to the percentage of patients who live at least five years or more after being diagnosed, but again, most bile duct cancer patients far outlive this five-year span. The survival rates are also grouped into localized, regional, and distant bile duct cancers; localized refers to Stage I tumors, regional refers to Stage II and III tumors, and distant refers to Stage IV tumors.

Treatment of Bile Duct Cancer

The treatments available for various bile duct cancer types and stages range from surgical procedures, to radiation, to a combination of many different treatment methods, which is most often the case. While surgery is the most common and most successful treatment- at least in terms of removing as much of the cancerous area as possible- radiation therapy, chemotherapy, and palliative therapy are all bile duct cancer treatment options as well. The initial treatment suggested will almost always depend on whether a patient's tumor is considered resectable, or removable by surgery; imaging tests and other diagnostic techniques will aid doctors in making as conclusive of a decision regarding this as possible. If the tumor is likely to be removed by surgery- most stage 0, I, II and some stage II bile duct cancers are- then a surgical procedure removing a part (or several parts) of the biliary system, in conjunction with radiation or chemotherapy, may be offered. If diagnostic tests show that the tumor is too large or has spread too far to be successfully removed, however, then usually radiation, chemotherapy, and/or a range of palliative therapies will be used to see if the cancer can at all be minimized before s surgical attempt is made. A liver transplant is also a possibility for certain bile duct cancer patients, however due to the liver donor waiting list, this is usually only suggested if a cancer is deemed curable.

While several factors of bile duct cancer- such as the development of the cancer in later stages of life- make it somewhat difficult to construct early screening methods, and so, early bile duct cancer diagnosis is still fairly infrequent, every year, bile duct cancer research continues to improve, and so new information about the cancer and its affect on genes are bound to bring substantial improvements. New treatment possibilities and combinations are similarly being tested by cancer researchers to help improve upon current therapies, so progress is slowly, but surely being made in the field of bile duct cancer, giving hope of a cure to all patients afflicted with this rare disease.