Bile Duct Cancer Staging

The stage describes the extent of cancer in the body and whether it has spread, helping the doctor plan the best treatment. Doctors use the results of your physical exam, imaging and other tests, and surgical results (if you had surgery) to determine the stage. 

If they were not part of the diagnosis process, some additional tests may be needed. This staging process usually determines if there are cancer cells outside the bile ducts.

Bile duct cancer stages are described using the TNM staging system, which stands for:

  • T = Tumor size
  • N = Lymph Node status (the number and location of lymph nodes with cancer)
  • M = Metastases (whether or not the cancer has spread to other parts of the body)

The system classifies cancers in stages I through IV (1 through 4). As a rule, the lower the number, the less the cancer has spread. Bile duct cancers have 3 different staging systems based on their origin.

Below are the stages for each type of bile duct cancer: 

Intrahepatic Bile Duct Cancer Stages

  • Stage 0: In this stage, abnormal cells are found in the innermost layer of tissue lining the intrahepatic bile duct. These cells are not cancerous yet, but they have the potential to become cancerous and spread into nearby normal tissue.
  • Stage I: Stage I intrahepatic bile duct cancer is divided into stages IA and IB.
    • In stage IA, the tumor is 5 centimeters or smaller.
    • In stage IB, the tumor is larger than 5 centimeters.
  • Stage II: In this stage, the tumor has either: 
    • spread through the wall of the intrahepatic bile duct and into a blood vessel, or
    • more than one tumor has formed in the intrahepatic bile duct and may have spread into a blood vessel.
  • Stage III: Stage III intrahepatic bile duct cancer is divided into stages IIIA and IIIB.
    • In stage IIIA, the tumor has spread through the outer lining of the liver
    • In stage IIIB, the cancer has spread to nearby organs or tissues or nearby lymph nodes.
  • Stage IV: In this stage, the cancer has spread to other parts of the body, such as the bone, lungs, distant lymph nodes, or tissue lining the wall of the abdomen and most organs in the abdomen.

Stages of Perihilar Bile Duct Cancer

  • Stage 0 (carcinoma in situ): Abnormal cells are found in the innermost layer of tissue lining the perihilar bile duct, which may become cancerous and spread into nearby normal tissue.
  • Stage I: Cancer has formed in the innermost layer of tissue lining the perihilar bile duct and has spread into the muscle layer or fibrous tissue layer of the perihilar bile duct wall.
  • Stage II: Cancer has spread through the wall of the perihilar bile duct to nearby fatty tissue or liver tissue.
  • Stage III: Stage III perihilar bile duct cancer is divided into sub-stages IIIA, IIIB, and IIIC:
    • Stage IIIA: Cancer has spread to branches on one side of the hepatic artery or of the portal vein.
    • Stage IIIB: Cancer has spread to specific areas, such as the main part of the portal vein or its branches, the common hepatic artery, the right hepatic duct and the left branch of the hepatic artery or of the portal vein, or the left hepatic duct and the right branch of the hepatic artery or of the portal vein.
    • Stage IIIC: Cancer has spread to 1 to 3 nearby lymph nodes.
  • Stage IV: Stage IV perihilar bile duct cancer is divided into sub-stages IVA and IVB:
    • Stage IVA: Cancer has spread to 4 or more nearby lymph nodes.
    • Stage IVB: Cancer has spread to other parts of the body, such as the liver, lung, bone, brain, skin, distant lymph nodes, or tissue lining the wall of the abdomen and most organs in the abdomen.

Distal Bile Duct Cancer Stages

  • Stage 0: In stage 0 distal bile duct cancer (carcinoma in situ), abnormal cells are found in the innermost layer of tissue lining the distal bile duct. These abnormal cells are not cancerous but may become cancerous and spread into nearby normal tissue. Stage 0 is also called high-grade dysplasia.
  • Stage I: Cancer has formed and spread fewer than 5 millimeters into the wall of the distal bile duct.
  • Stage II: Stage II distal bile duct cancer is divided into stages IIA and IIB.
    • Stage IIA: Cancer has spread fewer than 5 millimeters into the wall of the distal bile duct and has spread to 1 to 3 nearby lymph nodes or 5 to 12 millimeters into the wall of the distal bile duct.
    • Stage IIB: Cancer has spread 5 millimeters or more into the wall of the distal bile duct. Cancer may have spread to 1 to 3 nearby lymph nodes.
  • Stage III: Stage III distal bile duct cancer is divided into stages IIIA and IIIB.
    • Stage IIIA: Cancer has spread into the wall of the distal bile duct and to 4 or more nearby lymph nodes.
    • Stage IIIB: Cancer has spread to the large vessels that carry blood to the organs in the abdomen. Cancer may have spread to 1 or more nearby lymph nodes.
  • Stage IV: Cancer has spread to other parts of the body, such as the liver, lungs, or tissue lining the wall of the abdomen and most organs in the abdomen.

The TNM staging system offers a detailed overview of how far the bile duct cancer has spread and provides your oncologist with insight into your prognosis (outlook). However, for treatment purposes, a less complex system is often used based on whether your cancer can be surgically removed:  

  • Resectable (localized) bile duct cancer: This type of cancer is in a specific area, such as the lower part of the common bile duct or the perihilar area, where it can be completely removed by surgery.
  • Unresectable (including metastatic and recurrent) bile duct cancer: This type of cancer cannot be completely removed by surgery. In most cases, people with bile duct cancer cannot have their cancer completely removed by surgery.

Usually, the earlier the stage of the cancer (0, I, II) the higher the chance of it being resectable. Most advanced-stage (III and IV) tumors are unresectable. However, this depends on other factors, such as the size and location of the cancer, as well as your overall health and ability to undergo surgery.  

Understanding the extent of your bile duct cancer will help the oncologist recommend the best treatment for you. Whether your cancer is resectable will affect the types of treatments used. Surgery is the preferred approach since it offers the best chance of a cure. If the cancer has not spread and is in a reachable location, the surgeon will remove the tumor and some surrounding tissue, reducing the likelihood of the cancer recurring. Depending on your situation, you might receive a combination of treatments.