Bile Duct Cancer

Cancer arising in the bile duct is known as bile duct cancer or cholangiocarcinoma. Bile duct cancer is the second most common cancer of the liver.

Associated Anatomy

liver, bile duct.

Alternate Names of Bile Duct Cancer

• Cholangiocarcinoma
• Cholangiocarcinoma of biliary tract
• Cholangiocellular carcinoma
• Perihilar or hilar cholangiocarcinoma
• Distal cholangiocarcinoma
• Intrahepatic cholangiocarcinoma
• Extrahepatic cholangiocarcinoma

Signs and Symptoms of Bile Duct Cancer

• Yellow eyes or skin (jaundice): Jaundice is the most common presenting complaint. It is caused by the obstruction of the bile duct due to cancer, which results in the stagnancy of bile juice and causes cholangitis.
• Abdominal Pain.
• Indigestion.
• Loss of appetite.
• Weight loss.
• Vomiting.
• Fever.
• Light-coloured stools (bile salts are responsible for the brown colour of stools. In the absence of bile, the stools are pale or clay-colored)

Bile Duct Cancer Causes

The exact causative factors of bile duct cancer or cholangiocarcinoma are unknown. Cancer is a result of an oncogenic (cancer-producing gene) gene activation that can occur due to various reasons. Though the exact mechanism is unknown, a few pathologic reasons are known.

• Untreated inflammatory conditions such as bile duct inflammation (cholangitis) and large intestine inflammation (ulcerative cholangitis).
• Minor or small undiagnosed stones are present in bile ducts and gallbladders.
• Infections such as liver fluke.
• Alcoholism.
• Age.
• Obesity.
• Diabetes.
• Family history of cholangiocarcinoma (Not a direct cause).
• Metastasis of primary cancer (cancer spread from other parts of the body).
• Smoking.
• Birth defects in bile ducts.

Types of Bile Duct Cancer:

Bile duct cancer is divided into the following two major types based on the location of the tumor:

• Intrahepatic (Inside the liver)
• Extrahepatic (Outside the liver)

Extrahepatic Bile duct cancer is further divided into perihilar cancer (cancer in the common hepatic duct of the liver) and distal cancer (cancer in the common bile duct of the liver).

Perihilar tumor or Klatskin tumor arising at the junction of right and left hepatic duct.

Distal tumors in the distal part of the bile duct.

The most common type of bile duct cancer is the extrahepatic type of cancer. Intrahepatic cancer contributes to 10-15% of bile duct cancers.

This type of cancer presents with a moderate to poor prognosis. It is responsible for 7.6% of cancer deaths globally.

Possible Bile Duct Cancer Treatment

Based on cancer's extent and type, Bile Duct Cancer Treatment options can vary. Surgery helps to resect cancer and other associated parts. Radiotherapy, immunotherapy, and chemotherapy are used if the extent of the cancer is less. Your doctor will take you through the Bile Duct Cancer Treatment plans and procedures.

Prevention of Bile Duct Cancer Treatment

Primary prevention

• Maintain BMI on the healthier side.
• Practice good hygiene.
• Ensure food items are thoroughly cooked before consumption.
• Quit smoking and limit alcohol intake.

Secondary Prevention

• Avoid exposure to chemicals listed above in risk factors.
• Screening for possible genetic mutations on exposure to cancer-producing chemicals.
• Screening for primary sclerosing cholangitis by CA 19-9 may be helpful.

Risk Factors of Bile Duct Cancer

• Long-term inflammatory diseases such as primary sclerosing cholangitis, Crohn’s disease, and ulcerative cholangitis.
• Cirrhosis (liver damage leading to liver scarring and liver failure).
• Hepatolithiasis (Gallstones present in the bile duct).
• Fibropolycystic liver disease (Cysts present in liver).
• Hepatitis B and C virus infection.
• Premalignant lesions such as biliary intraepithelial neoplasia.
• Infestation of liver fluke worm.
• Exposure to allergens especially chemicals like dioxins, nitrosamines, and polychlorinated biphenyls (PCBs).

Possible Complications in Bile Duct Cancer

• Bile duct obstruction and cholangitis- Bile duct obstruction is one common complication of cholangiocarcinoma. The obstruction can lead to infection, cell death, and cirrhosis.
• Cirrhosis.
• Complications of chemotherapy, radiation therapy, and surgery.
• Complications of surgery are bile leak, liver failure, and GI bleeding.

Medical Tests Required For Bile Duct Cancer

• Blood profile.
• The liver function test (LFT) helps in accessing the bilirubin level (jaundice) with which you can access the presence of jaundice.
• Tumor marker test- CA 19-9 or carbohydrate antigen 19-9 is a protein produced by bile duct cancer cells, and it is released into the bloodstream. Its level helps to detect the presence of bile duct cancer and also detect inflammation and obstruction.
• Percutaneous transhepatic cholangiography (PTC)
• Tissue Biopsy -Used to identify the type of cancer cells present. A small piece of bile duct tissue removed from the cancer mass is accessed under the microscope.

Imaging Techniques

• Abdominal ultrasound
• CT Scan
• MRI

Imaging techniques that use micro cameras to take pictures:

• Endoscopy
• Endoscopic retrograde cholangiopancreatography (ERCP)
• Magnetic resonance cholangiopancreatography (MRCP)
• Cholangioscopy

Epidemiology

Considering the prevalence of bile duct cancer, Klatskin tumor (extrahepatic bile duct cancer) is the most common type, involving 50-60% of the cases.

Intrahepatic type is the least common type, accounting for 10% of the total cholangiocarcinoma.

Prognosis

Bile duct cancers have moderate to poor prognosis (recovery).

For the Intrahepatic type, the approximate (median) time between diagnosis and death is short compared to the extrahepatic type.

The extrahepatic type has a 15% survival rate from the period of diagnosis. This is mainly because of the nature of cancer presentation. There won't be any presentation in the initial stage. Many people show symptoms at the later stages with bile duct obstruction.

Natural Progression

Adjacent tissue involvement- Cancer cells metastasize to adjacent tissue and organs.

Distant Metastasis- Cancer cells migrate from the liver to other distant organs and form metastatic cancer.

Medical Management

• Bile drainage - bypassing the obstruction and clearing the duct passage.
• Radiation therapy
• Chemotherapy
• Targeted drug therapy
• Immunotherapy
• Photodynamic therapy
• Surgery
• Liver transplant- It is rarely indicated. Usually, adjuvant chemoradiation therapy is given for liver transplantation.
• Supportive or palliative care

Surgical Management:

The management option varies from individual to individual based on their cancer type and severity. Surgery for cholangiocarcinoma depends on the site of the tumor and its extent.

A total of 70% of cases are unsuitable for surgery due to progressing disease. Patients with unresectable cancer are given palliative care to improve their quality of life during difficult times by giving symptomatic treatments and preventing the sequelae of the disease.

A total of 10-15% of patients are eligible for surgery.

Surgery aims to remove the tumor completely and reconstruct the biliary tree.