What is the incidence rate of cholangiocarcinoma?

Incidence Rate of Cholangiocarcinoma

The incidence of cholangiocarcinoma varies substantially worldwide, ranging from very high rates in Northeast Thailand (>80 per 100,000 population) to much lower rates in Western countries (0.3-3.5 per 100,000 population). 1

Global Variation in Incidence

Regional Differences

• Northeast Thailand: Highest global incidence (>80 per 100,000) 1
• Western countries: Much lower rates
  • Canada: 0.3 per 100,000 1
  • United States: 0.9-1.26 per 100,000 1, 2
  • Europe: 0.3-3.5 per 100,000 3
• Asia (excluding Thailand):
  • Taiwan: Increased from 1.79 to 3.60 per 100,000 between 1998-2008 4
  • Korea: Higher rates compared to Western countries 5

Trends in Incidence

• Increasing trend in Western countries:

  • US: Increased by 165% from 0.3 per 100,000 (1975-1979) to 0.9 per 100,000 (1995-1999) 1, 6
  • Italy: Mortality rates increased from 0.2 to 5.9 per million between 1980-2003 1
  • Germany: Mortality more than tripled between 1998-2008 1

• Asian trends:

  • Korea: Annual percent change of 8% in males and 11% in females (1999-2005) 1
  • Taiwan: 2.01-fold increase from 1998 to 2008 4

Anatomical Classification and Subtype Trends

Distribution by Location

• 20-25% are intrahepatic (iCCA) 1
• 50-60% are perihilar tumors (pCCA) 1
• 20-25% are distal extrahepatic tumors (dCCA) 1
• About 5% may be multifocal 1, 3

Subtype-Specific Trends

• Intrahepatic cholangiocarcinoma (iCCA):

  • Showing the most dramatic increase globally 1, 2
  • US data (2001-2015): Annual percent change of 2.79% (2001-2007), 17.02% (2007-2010), and 9.67% (2010-2015) 2
  • Taiwan: 3.0-fold increase from 0.72 to 2.19 per 100,000 (1998-2008) 4

• Extrahepatic cholangiocarcinoma (ECC):

  • More stable or declining in some regions 6
  • Taiwan: 1.5-fold increase from 0.48 to 0.73 per 100,000 (1998-2008) 4
  • US: Declined by 14% (1975-1999) 6

Demographic Patterns

Age and Sex Distribution

• Incidence increases with age, with 65% of patients over 65 years old 1
• Slight male predominance (male to female ratio 1.2-1.5:1) 1
• US data shows men affected 1.5 times more than women 6

Ethnic Differences

• In the US (per 100,000):
  • All races: 0.9 (males) and 0.6 (females) 1
  • Whites: 0.9 (males) and 0.6 (females) 1
  • Blacks: 0.5 (males) and 0.2 (females) 1
  • Asian/Pacific Islanders: 1.3 (males) and 0.8 (females) 1
  • Hispanics: 1.2 overall, with higher rates in females (1.5) than males (0.9) 1
• Asians are affected almost 2 times more than whites and blacks in the US 6

Risk Factors Contributing to Regional Variations

High-Risk Conditions

• Primary sclerosing cholangitis (PSC): Lifetime risk 5-15% 1

  • Annual risk for cholangiocarcinoma in PSC patients: 0.5-1.0% 1
  • 10-year cumulative incidence: 6-11% 1
  • 30-year cumulative incidence: 20% 1
  • 400-fold higher risk than general population 1

• Liver flukes (Opisthorchis viverrini, Clonorchis sinensis): Major factor in Northeast Thailand 1

• Hepatolithiasis: More common in Southeast Asia (20%) than US (2%) 1

• Cirrhosis: Associated with 23-fold increased risk for iCCA 1

• Viral hepatitis:

  • HBV: Associated with iCCA (OR 5.5) 1
  • HCV: Associated with iCCA (OR 4.84) 1

• Other factors: Choledochal cysts, Caroli's disease, chronic typhoid carriers 1

Recent Emerging Risk Factors

• Diabetes: 81% increased risk of iCCA 1
• Obesity: 62% increased risk of iCCA 1
• Hormonal contraceptives: 62% increased risk of iCCA 1

Clinical Implications

The significant geographic variation and increasing incidence of cholangiocarcinoma, particularly iCCA, highlight the importance of awareness of risk factors and consideration of surveillance in high-risk populations. The rising incidence in Western countries despite stable or declining rates of known risk factors suggests additional unidentified risk factors may be contributing to this trend.

Mortality remains high with 5-year survival rates of only 3.5% 6, emphasizing the need for earlier detection strategies, particularly in high-risk groups.

The marked differences in incidence between regions and populations should guide resource allocation for prevention, screening, and treatment efforts, with particular attention to areas experiencing the most significant increases in incidence.

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