Risk factors for cholangiocarcinoma in a low risk Caucasian population.

OBJECTIVES: Little is known about the etiology of cholangiocarcinoma, apart from its association with liver fluke infestation. METHODS: A case-control study was conducted in Athens and included six cholangiocarcinoma cases, 333 hepatocellular carcinoma cases and 360 controls with minor ailments or injuries. All subjects were interviewed and tested for hepatitis B and C infection. For all six cholangiocarcinomas, 97 hepatocellular carcinomas and 129 controls, sex steroids were determined in the blood. RESULTS: Hepatitis B or C viruses, tobacco smoking, alcohol drinking and diabetes mellitus were not related to cholangiocarcinoma, but history of thyroid disease was. Estradiol levels were higher among cholangiocarcinoma cases than among the other two groups. CONCLUSIONS: This study provides evidence that endocrine and autoimmune factors are important in the etiology of cholangiocarcinoma.