. Author manuscript; available in PMC: 2012 Jul 1.

Published in final edited form as: Hepatology. 2011 Jul;54(1):173–184. doi: 10.1002/hep.24351

Table 2.

Cholangitis and Choledocholithiasis as Potential Risk factors for Cholangiocarcinoma

First author	Country	Study dates	Study design	Risk factor	CC type	Cases (% with risk factor)	Controls (% with risk factor)	Risk estimate (95% CI)	Selected adjusted variables
Welzel⁴⁸	Denmark	1978–1991	Case-Control	Cholangitis	ICC	764 (1.3%)	3,056 (0.23%)	6.32 (2.3–17.5)	Age, sex
				Choledocholithiasis	ICC	764 (0.79%)	3,056 (0.03%)	23.97 (2.9–198.9)
Shaib ⁴⁷	US	1993–1999	Case-control	Cholangitis	ICC	625 (3.4%)	90,834 (0.2%)	8.8 (4.9–16.0)	Age, sex, race, geographic location
				Choledocholithiasis	ICC	625 (1.1%)	90,834 (0.3%)	4.0 (1.9–8.5)
Welzel²⁸	US	1993–1999	Case-Control	Cholangitis	ICC	535 (12.5%)	102,782 (0.2%)	64.2 (47.7–86.5)	Age, sex, race, geographic location
				Choledocholithiasis	ICC	535 (11%)	102,782 (0.5%)	22.5 (16.9–30.0)
				Cholangitis	ECC	549 (9.1%)	102,782 (0.2%)	45.7 (32.9–63.6)
				Choledocholithiasis	ECC	549 (15.8%)	102,782 (0.5%)	34.0 (26.6–43.6)

CC = cholangiocarcinoma; ICC = intrahepatic cholangiocarcinoma; ECC = extrahepatic cholangiocarcinoma; CI = confidence interval