Cholangiocarcinoma is a rare form of cancer in the bile ducts. Every year, between 150 and 300 people in the Netherlands receive this diagnosis. Because the disease is often only discovered at a late stage, surgical intervention is in many cases no longer possible. Research is being conducted into how to effectively combat this form of cancer, and there is particular hope that targeted therapy could offer a solution in the future.
- What is cholangiocarcinoma?
- Symptoms of cholangiocarcinoma
- Risk factors
- Treatment and prospects
What is cholangiocarcinoma?
Cholangiocarcinoma is the medical term for a form of cancer that consists of mutated epithelial cells in the bile duct, where bile is transported from the liver to the small intestine. It differs from other types of cancer of the bile ducts such as pancreatic cancer, gallbladder cancer or cancer of the ampulla of Vater. A cholangiocarcinoma is a relatively rare form of neoplasm that is classified as an adenocarcinoma: a carcinoma that arises in glandular tissue or cells that have an excretory function. Only 1 to 2 in 100,000 people are diagnosed with cholangiocarcinoma every year. According to researchers, this number has increased somewhat in recent decades.
Symptoms of cholangiocarcinoma
The most common indications of cholangiocarcinoma are:
- Abnormal liver values
- Jaundice (yellowing of the skin and whites of the eyes)
- Changes in color of urine and stool
- Pruritis/itching all over the body (60 to 70%)
- Abdominal pain (30 to 50% of patients)
- Weight loss (30 to 50%)
- Fever (10 to 20%)
Lab tests of liver values in people with cholangiocarcinoma often show elevated values of bilirubin (and a waste product that is mainly released during the breakdown of old red blood cells), alkaline phosphatase (an enzyme that can remove phosphate groups from various molecules) and gamma-glutamyltransferase (an enzyme that transfers an amino acid). Elevated values here are an indication that there is an obstruction of the bile ducts, where the cause of jaundice is often inflammation. An increase in CA 19-9, a glycolipid present in pancreatic tissue and on the epithelium of the stomach and gallbladder, is also often measured. It can also be produced by some types of cancer cells and is therefore also used in medicine as a tumor marker.
The physical symptoms often depend on the location of the tumor. For example, jaundice mainly occurs in people whose tumor is located just outside the liver. If it is located in the liver, jaundice is much less common and pain is much more common. In addition to blood tests, MRI, endoscopy and sometimes keyhole surgery where a biopsy can be taken are also used to make the diagnosis.
Cancer is often caused by the consumption of dairy or red meat, smoking, lack of exercise and obesity. It has not been proven that such matters influence the development of cholangiocarcinoma. There are indications that primary sclerosing cholangitis (a disease in which the bile ducts inside and outside the liver are chronically inflamed) increases the risk of this. The same applies to congenital liver malformations, infection with the flukes Opisthorchis viverrini or Clonorchis sinensis (both of which occur in Asia). Exposure to thorotrast, a radioactive substance used in the 1930s and 1940s to take X-rays, can also affect it. However, in most people with cholangiocarcinoma, no direct cause can be found.
Treatment and prospects
Cholangiocarcinoma is considered incurable unless the primary tumor and metastases can be completely removed surgically. There is no medication that can effectively combat the disease. The disease is often only discovered at a late stage, which means that surgical intervention will often no longer provide a solution. Chemotherapy, radiation and other palliative care are often provided to make the disease bearable.
Recent research has shown that targeted therapy could offer a solution. This involves treatment with Erlotinib hydrochloride (Tarceva), which has been on the market since 2004 and is mainly used in the treatment of (metastatic) lung cancer and pancreatic cancer. It falls under the tyrosine kinase inhibitors.
In addition, research is also being conducted into combating cholangiocarcinoma through photodynamic therapy, a treatment that uses visible light and a substance (Porfimer sodium or Photofrin) that makes the cells so sensitive that they die.