An age old preference for eating uncooked fish dishes like koi-pla puts people in SE Asia at risk of ingesting trematodes that can cause a type of liver cancer called cholangiocarcinoma (cancer of the bile ducts), say researchers in this week's PLoS Medicine.
Banchob Sripa (Khon Kaen University) and colleagues discuss the mechanisms by which the food-borne trematode Opisthorchis viverrini (the SE Asian liver fluke) causes cholangiocarcinoma. The fluke is endemic to Thailand, Lao People's Democratic Republic, Vietnam, and Cambodia. In Thailand alone, 6 million people are thought to be infected with the fluke.
Alternative namesBile duct cancer
http://www.adam.com">Cholangiocarcinoma is a malignant (cancerous) growth in one of the ducts that carries bile from the liver to the small intestine.
Causes, incidence, and risk factors
Malignant tumors of the bile ducts are usually slow-growing and late to spread (metastasize). Nonetheless, by the time a diagnosis is made, many of these tumors are too advanced to be removed surgically.
A cholangiocarcinoma may arise anywhere along the liver secretion (biliary) ducts. These tumors produce symptoms by blocking the bile ducts. They affect both sexes, and a majority of cases are found in patients above the age of 65.
Primary sclerosing cholangitis, choledochal (bile duct) cysts, and chronic biliary irritation are all associated with increased risk for this condition. Cholangiocarcinoma is rare, occurring in approximately 2 out of 100,000 people.
- Stools, clay colored
- Progressive jaundice
- Right upper abdominal pain that may radiate to the back
- Loss of appetite
- Weight loss
Signs and tests
Tests that show tumor or obstruction in the bile duct:
Blood tests that reveal abnormal function:
- ERCP (endoscopic retrograde cholangiopancreatography)
- PTCA (percutaneous transhepatic cholangiogram)
- Abdominal CT scan
- Abdominal ultrasound
- CT scan-directed biopsy
- Liver function tests
The goal is to treat the cancer and the obstruction it causes. When possible, surgical removal of the tumor is the treatment of choice and may result in cure. Chemotherapy or radiation may be given after surgery to decrease the risk of recurrence, but the benefit of this is not entirely clear.
Endoscopic therapy or surgery can clear obstructions in the biliary ducts and relieve jaundice in patients in whom the tumor is unresectable (cannot be removed).
For patients with unresectable disease, radiation therapy may be beneficial. Chemotherapy may be added to radiation therapy or used when tumor has spread outside of the biliary tree. However, this is rarely effective.
The stress of illness can often be eased by joining a support group with members who share common experiences and problems. For this condition, see cancer - support group. Hospice is often a good resource for patients with cholangiocarcinoma that cannot be cured.
Complete tumor removal allows 30% to 40% of patients to survive for at least 5 years, with the possibility of a complete cure. If the tumor cannot be completely removed, cure is generally not possible. In this situation, with treatment, about half of patients live a year, and about half live longer.
- Spread (metastasis) of tumor to other organs
- Liver failure