If you're diagnosed with hilar cholangiocarcinoma, also called perihilar cholangiocarcinoma or Klatskin tumor, the next step is to determine where the cancer is and how far it has spread, called the stage. Staging may include imaging tests such as MRI, CT scans, PET scans or X-rays. The images help your healthcare team see the cancer's location and any spread.
How staging works
For hilar cholangiocarcinoma, healthcare professionals often use two different systems to learn about the cancer. Together, these systems help guide treatment and predict outcomes:
- Bismuth-Corlette classification. This system describes the location of the cancer in the bile ducts.
- TNM staging. This system describes how far the cancer has spread.
Bismuth-Corlette classification
The Bismuth-Corlette system divides hilar cholangiocarcinoma into four main types based on how far the cancer extends into the bile ducts:
- Type 1. In type 1, the cancer is below the junction of the right and left hepatic ducts.
- Type 2. In type 2, the cancer reaches the junction but does not extend into the right or left ducts.
- Type 3a. In type 3a, the cancer extends into the right hepatic duct.
- Type 3b. In type 3b, the cancer extends into the left hepatic duct.
- Type 4. In type 4, the cancer involves both the right and left hepatic ducts.
This system helps surgeons decide how much of the bile duct and liver may need to be taken out.
TNM staging
The TNM system is the standard for describing cancer stages. The system looks at three main features:
- T. The size of the primary tumor.
- N. Whether the cancer has spread to nearby lymph nodes.
- M. Whether the cancer has spread to other parts of the body, called metastasis.
Healthcare professionals use these features to assign a stage from 1 to 4.
Hilar cholangiocarcinoma stages
Stage 1
At stage 1, the cancer has grown deeper into the wall of the bile duct but has not spread to nearby lymph nodes or other organs.
It is considered localized, meaning the cancer is confined to the bile duct area and can often be treated with surgery to take out the affected section of the bile duct and nearby tissue.
Stage 2
In stage 2 hilar cholangiocarcinoma, the cancer has grown beyond the wall of the bile duct into nearby fat or liver tissue, but it still has not spread to lymph nodes or distant organs.
Surgery to remove the bile ducts and part of the liver may be done along with removal of nearby lymph nodes to check for hidden spread.
Stage 3
Stage 3 means the cancer has spread to nearby lymph nodes or major blood vessels that supply the liver. The cancer also may cause part of the liver to shrink, called atrophy, on one side. Because of this, surgery becomes more complex and may require major liver resection.
Additional treatments such as chemotherapy or radiation therapy may be used before or after surgery to help control the disease.
Stage 4
In stage 4, the cancer has spread to other organs such as the liver, lungs, distant lymph nodes or the lining of the abdomen, called the peritoneum. This stage also is called metastatic disease.
Surgery is usually not possible. Treatment focuses on systemic therapy such as chemotherapy, targeted therapy or immunotherapy to slow the cancer and ease symptoms.