Intrahepatic cholangiocarcinoma (staging)

Intrahepatic cholangiocarcinoma staging is conducted most commonly in accordance with the TNM staging classification of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC). As of 2018, the staging criteria are in their 8^th edition and reflected below ¹. The rare mixed hepatocholangiocarcinoma (combined hepatocellular and cholangiocarcinoma) is also staged according to the intrahepatic bile duct classification ². However, cancers of the perihilar and distal bile ducts are staged differently.

Primary tumor (T)

• TX: primary tumor cannot be assessed 
• T0: no evidence of primary tumor
• Tis: carcinoma in situ (intraductal tumor)
• T1: solitary tumor without vascular invasion
  • T1a: solitary tumor ≤5 cm without vascular invasion
  • T1b: solitary tumor >5 cm without vascular invasion​
• T2: 
  • solitary tumor with intrahepatic vascular invasion or,
  • multiple tumors, with or without vascular invasion​
• T3: tumor perforating the visceral peritoneum
• T4: tumor involving local extrahepatic structures by direct invasion

Regional lymph node (N)

• NX: regional lymph nodes cannot be assessed
• N0: no regional lymph node metastasis
• N1: regional lymph node metastasis present

Distant metastases (M)

• cM0: no evidence of metastases
• cM1: distant metastasis
• pM1: distant metastasis, microscopically confirmed

Stage groups

• stage 0
  • ​Tis, N0, M0
• stage IA
  • T1a, N0, M0
• stage IB
  • T1b, N0, M0
• stage II
  • T2, N0, M0
• stage IIIA
  • T3, N0, M0 
• stage IIIB
  • T4, N0, M0
  • [Any T], N1, M0
• stage IV
  • [Any T], [Any N], M1

Prognosis

The 5-year survival for each stage of intrahepatic cholangiocarcinoma in the AJCC 8^th edition is as follows ³:

• stage IA: 58%
• stage IB: 45%
• stage II: 31%
• stage IIIA: 24%
• stage IIIB: 12%
• stage IV: 9%