Staging of Intrahepatic Bile Duct Cancers

After someone is diagnosed with intrahepatic bile duct cancer, doctors will try to figure out if it has spread, and if so, how far. This process is called staging. The stage of a cancer describes how much cancer is in the body. It helps determine how serious the cancer is and how best to treat it. Doctors also use a cancer's stage when talking about survival statistics.

The earliest stage intrahepatic bile duct cancers are stage 0 (also called carcinoma in situ, or CIS), and then range from stages I (1) through IV (4). As a rule, the lower the number, the less the cancer has spread. A higher number, such as stage IV, means cancer has spread more. And within a stage, an earlier letter means a lower stage. Although each person’s cancer experience is unique, cancers with similar stages tend to have a similar outlook and are often treated in much the same way.

How is the stage determined?

The staging system most often used for intrahepatic bile duct cancer is the American Joint Committee on Cancer (AJCC) TNM system, which is based on 3 key pieces of information:

  • The extent (size) of the main tumor (T): How large has the cancer grown? Has the cancer reached nearby structures or organs?
  • The spread to nearby lymph nodes (N): Has the cancer spread to nearby lymph nodes?
  • The spread (metastasis) to distant sites (M): Has the cancer spread to distant lymph nodes or distant organs such as the bones, lungs, or peritoneum (the lining of the abdomen)?

The system described below is the most recent AJCC system, effective January 2018. It is used only for intrahepatic bile duct cancers (those starting within the liver). Staging systems for cancers starting in other parts of the bile ducts are described in:

Numbers or letters after T, N, and M provide more details about each of these factors. Higher numbers mean the cancer is more advanced.

Once a person’s T, N, and M categories have been determined, this information is combined in a process called stage grouping to assign an overall stage. For more information, see Cancer Staging.

Intrahepatic bile duct cancer is typically given a clinical stage based on the results of a physical exam, biopsy, and imaging tests (as described in How Is Bile Duct Cancer Diagnosed?). If surgery is done, the pathologic stage (also called the surgical stage) is determined by examining tissue removed during the operation. 

Cancer staging can be complex, so ask your doctor to explain it to you in a way you understand.

Stages of intrahepatic bile duct cancer

AJCC Stage

Stage grouping

Stage description*

0

Tis

N0

M0

The cancer is only in the mucosa (the innermost layer of cells in the bile duct). It has not started growing into the deeper layers (Tis).

It has not spread to nearby lymph nodes (N0) or to distant sites (M0).

IA

T1a

N0

M0

The tumor is no more than 5 cm (about 2 inches) across and has not invaded nearby blood vessels (T1a).

It has not spread to nearby lymph nodes (N0) or to distant sites (M0).

IB

T1b

N0

M0

The tumor is more than 5 cm (about 2 inches) across but has not invaded nearby blood vessels (T1b).

The cancer has not spread to nearby lymph nodes (N0) or to distant sites (M0).

II

T2

N0

M0

The tumor has grown into nearby blood vessels, OR there are 2 or more tumors, which might or mmight not have grown into nearby blood vessels (T2).

The cancer has not spread to nearby lymph nodes (N0) or to distant sites (M0).

 

IIIA

 

T3

N0

M0

The cancer has grown through the visceral peritoneum (the outer lining of organs in the abdomen) (T3).

The cancer has not spread to nearby lymph nodes (N0) or to distant sites (M0).

IIIB

T4

N0

M0

The cancer has grown directly into structures outside of the liver (T4).

The cancer has not spread to nearby lymph nodes (N0) or to distant sites (M0).

OR

Any T

N1

M0

The cancer is any size and might or might not be growing outside the bile duct (Any T).

It has spread to nearby lymph nodes (N1) but not to distant sites (M0).

IV

Any T

Any N

M1

The cancer is any size and might or might not be growing outside the bile duct (Any T). It might or might not have spread to nearby lymph nodes (any N).

It has spread to distant organs such as the bones or lungs (M1).

 

*The T categories are described in the table above, except for:

  • TX: Main tumor cannot be assessed due to lack of information.
  • T0: No evidence of a primary tumor.

The N categories are described in the table above, except for:

  • NX: Nearby lymph nodes cannot be assessed due to lack of information.

 

 

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

American Joint Committee on Cancer. Intrahepatic Bile Ducts. In: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer; 2017: 295-302.

Last Medical Review: December 8, 2017 Last Revised: December 8, 2017

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