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Distal stages and grades

Distal bile duct cancer starts in the bile ducts near the bowel. Find out how doctors stage and grade this type of bile duct cancer. 

Diagram showing the position of the distal bile ducts

The stage of a cancer tells you its size and whether it has spread. Your doctor looks at your scans and x-rays to work out the stage. This helps them to decide what treatment you need.

The grade describes how abnormal the cancer cells are compared to healthy cells. A specialist doctor (pathologist) works out the grade by looking at a sample of cells under the microscope.

Bile duct cancer is also known as cholangiocarcinoma. There are different ways of staging the different types of bile duct cancer. For distal bile duct cancer doctors use the:

  • TNM system
  • number staging system

TNM staging system

TNM stands for Tumour, Node and Metastasis. The system describes: 

  • how far the primary tumour has grown (T)
  • whether the cancer has spread to the lymph nodes (N)
  • whether the cancer has spread to a different part of the body (M)

T stages

T describes how far the cancer (tumour) has grown. There are 4 main T stages for distal bile duct cancer – T1 to T4:

T1 means the tumour is inside the bile duct and has grown less than 5mm into the bile duct wall.

T2 means the tumour has grown between 5 and 12 mm into the wall of the bile duct.

T3 means the tumour has grown more than 12mm into the wall of the bile duct.

T4 means the tumour is growing into nearby blood vessels, including the celiac artery, the superior mesenteric artery, or the common hepatic artery.

N stages

N describes whether the cancer has spread to the lymph nodes. There are 3 stages – N0, N1 and N2: 

N0 means there are no cancer cells in the lymph nodes.

N1 means there are cancer cells in 1 to 3 of the nearby lymph nodes.

N2 means there are cancer cells in 4 or more of the nearby lymph nodes

M stages

M describes whether the cancer has spread to another part of the body (metastases). There are 2 stages - M0 and M1:

M0 means there is no sign of cancer spread.

M1 means the cancer has spread to other parts of the body such as the lungs.

Number stages

There are 4 main number stages for distal bile duct cancer - stage 1 to stage 4.

Stage 1

Stage 1 means the tumour has grown less than 5mm into the bile duct wall. This is the same as T1, N0, M0 in the TNM staging system.

Stage 2

Stage 2 is split into 2 groups – stage 2A and stage 2B

Stage 2A means the tumour has grown less than 5mm into the bile duct wall and there are cancer cells in 1 to 3 of the nearby lymph nodes. (T1, N1, M0)

Or the tumour has grown 5 to 12mm into the bile duct wall and has not spread to the lymph nodes (T2, N0, M0).

Stage 2B means the tumour has grown between 5 and 12mm into the bile duct wall and has spread to 3 or less lymph nodes (T2, N1, M0).

Or the tumour has grown more than 12mm into the bile duct wall and may have spread to 3 lymph nodes or less (T3, N0 or N1, M0).

Stage 3

Stage 3 is split into 2 groups - stage 3A and 3B.

Stage 3A means the tumour has grown up to 12mm or more into the bile duct wall. And it has spread to 4 or more nearby lymph nodes (T1, 2 or 3, N2, M0).

Stage 3B means the tumour has grown into the main blood vessels and there may or may not be cancer cells in the lymph nodes (T4, N0, 1 or 2, M0).

Stage 4

Stage 4 means the cancer has spread to other parts of the body such as the lungs. This is the same as Any T, Any N and M1 in the TNM staging system.

Grades of distal bile duct cancer

The grade of a cancer is a way of measuring how abnormal cancer cells are compared to healthy cells. It also gives an idea of how quickly a cancer may grow and whether it is likely to spread.

Low grade cancers are usually slower growing and less likely to spread. High grade cancers tend to be faster growing and more likely to spread.

There are 3 grades of distal bile duct cancer - grade 1 to grade 3:

Grade 1

Grade 1 cancer means the cancer cells look similar to normal bile duct cells. This is called low grade cancer.

Grade 2

Grade 2 cancer means the cancer cells look slightly different to normal bile duct cancers. This is called intermediate grade cancer.

Grade 3

Grade 3 cancer means the cancer cells look very abnormal and unlike normal bile duct cells. This is called high grade cancer.

Differentiation

Differentiation means how developed or mature a cell is. Cancer cells are not as mature as normal cells.

You may hear your doctor describe:

  • grade 1 cancer cells as well differentiated
  • grade 2 cancer cells as moderately differentiated
  • grade 3 cancer cells as poorly differentiated
Last reviewed: 
06 Feb 2018
  • AJCC Cancer Staging Manual (8th edition)
    M Amin and others
    Springer, 2017.

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