Staging and grading of bile duct cancer

The stage of a cancer describes its size and whether it has spread from where it started. Knowing the stage of the cancer helps doctors decide on the best treatment for you.

The most commonly used staging systems for bile duct cancer are the number and TNM staging systems. Staging for bile duct cancer is different depending on where the cancer in the bile ducts began.

We have more information about staging for:

• intrahepatic bile duct cancer – (bile ducts inside the liver)
• perihilar bile duct cancer – (bile ducts just outside the liver)
• distal bile duct cancer – (bile ducts closest to the bowel).

There are four stages of bile duct cancer:

• Stage 1 – the cancer is small and only in one area of the bile ducts (localised cancer).
• Stages 2 and 3 – the cancer is larger and may have grown into part of the body close to the bile ducts. There may also be cancer cells in nearby lymph nodes (locally advanced cancer).
• Stage 4 – the cancer has spread to a part of the body far from the bile ducts (secondary or metastatic cancer).

• T describes the size of the tumour.
• N describes whether the cancer has spread to the lymph nodes.
• M describes whether the cancer has spread to another part of the body (this is called metastatic or secondary cancer).

This system gives detailed information about the tumour stage.

Tumour (T)

• Tis – the tumour is only in the first layer of the bile duct.
• T1 – the tumour has grown into deeper layers of the bile duct wall.
• T2 – the tumour has grown through the bile duct wall and into nearby fatty tissue or liver tissue.
• T3 – the tumour has grown into large blood vessels leading to the portal vein or hepatic artery.
• T4 – the tumour has grown into a blood vessel that is joined to one of the main blood vessels of the liver (the portal vein and the hepatic artery).

Nodes (N)

• N0 – the cancer has not spread to nearby lymph nodes.
• N1 – the cancer has spread to 1 to 3 nearby lymph nodes.
• N2 – the cancer has spread to four or more nearby lymph nodes.

Metastases (M)

• M0 – the cancer has not spread to parts of the body that are far away from the bile duct.
• M1 – the cancer has spread to parts of the body that are far away from the bile duct. For example, it has spread to the bones, lungs or distant parts of the liver.

There are five main stages of perihilar bile duct cancer.

Stage 0

The tumour is only in the first layer of the bile duct. It has not grown into deeper layers.

Stage 1

There is only one tumour and it is only in the bile duct.

Stage 2

The tumour has grown through the bile duct wall and into nearby fatty tissue or liver tissue.

Stage 3

The tumour has grown into one or more of the blood vessels that are joined to one of the main blood vessels of the liver.

Or the tumour has grown into one of the main blood vessels of the liver (the portal vein or hepatic artery). It may also have grown into more bile ducts. Or it might have grown into all three places.

Stage 3 could also mean that the cancer has spread to 1 to 3 nearby lymph nodes.

Stage 4

The cancer has grown into four or more lymph nodes. Or it has spread to parts of the body that are far away from the bile duct. For example, it has spread to the bones, lungs or distant parts of the liver.

When planning treatment for bile duct cancer, doctors use the terms resectable or unresectable. This describes whether it might be possible to remove (resect) the tumour with surgery:

• Resectable tumours are ones that doctors think it may be possible to remove with surgery
• Unresectable tumours cannot be removed with surgery. This might be because the cancer has spread to parts of the body far from the bile ducts. Or, it may be because the cancer is affecting important structures (such as large blood vessels) that cannot be removed.

Early stage cancers (stage 1 or 2) are often resectable. Some stage 3 cancers may also be resectable. When deciding whether a cancer is resectable, the doctor also needs to consider the position of the cancer and your general health.