Distal bile duct cancer starts in the bile ducts below the perihilar region near the bowel. Find out about how doctors stage and grade this type of bile duct cancer.
The stage of a cancer tells you how far it has grown or spread. The grade describes how abnormal the cancer cells are compared to healthy cells.
The stage and grade are important because your specialist uses this information to decide which treatment is most suitable for you.
Your scans and tests will give some information about the stage and grade of your cancer.
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 describes how far the cancer (tumour) has grown. There are 5 main T stages for distal bile duct cancer – Tis to T4:
Tis means the tumour is only within the top layers of cells lining the bile duct.
T1 means the tumour is entirely inside the bile duct but has grown deeper into the bile duct wall.
T2 means the tumour has grown through the wall of the bile duct.
T3 means the tumour has grown into the gallbladder, pancreas, small bowel (duodenum, ileum) or other nearby organs.
T4 means the tumour has grown into the major blood vessel in the abdomen (the aorta) where it joins the main blood vessel of the liver (the hepatic artery).
N describes whether the cancer has spread to the lymph nodes. There are 2 stages - N0 and N1:
N0 means there are no cancer cells in the lymph nodes.
N1 means there are cancer cells in the lymph nodes.
M describes whether the cancer has spread (metastasised) to another part of the body. 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 away from the bile duct.
There are 4 main number stages of distal bile duct cancer - stage 1 to stage 4.
Stage 1 has 2 groups - stage 1a and stage 1b:
Stage 1a means the tumour is completely inside the bile duct.
Stage 1b means the tumour has grown through the wall of the bile duct.
Stage 2 has 2 groups - stage 2a and 2b:
Stage 2a means the tumour has grown into the gallbladder, the pancreas or the small bowel.
Stage 2b means there are cancer cells in the lymph nodes.
Stage 3 means that the tumour has grown into the part of the main blood vessel (the aorta) where it joins the main blood vessel of the liver (the hepatic artery).
Stage 4 means the cancer has spread to other parts of the body.
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 4 grades of distal bile duct cancer - grade 1 to grade 4:
Grade 1 cancer means the cancer cells look very like normal bile duct cells. This is called low grade cancer.
Grade 2 cancer means the cancer cells look slightly different to normal bile duct cancers. This is called intermediate grade cancer.
Grade 3 cancer means the cancer cells look abnormal and unlike normal bile duct cells. This is called high grade cancer.
Grade 4 cancer means the cancer cells look very abnormal and nothing like normal bile duct cancer cells. This is also called high grade cancer.
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
- grade 4 cancer cells as undifferentiated