Data show that viral genotype 1 may increase the risk of cirrhosis and hepatocellular carcinoma (HCC) compared to genotype 2 in patients with chronic hepatitis C virus (HCV) infection. However, the effect of HCV genotype 3 on cirrhosis and HCC risk is uncertain. We identified patients with active HCV infection, confirmed by positive PCR and a known HCV genotype, from the VA HCV Clinical Case Registry between 2000 and 2009. We examined the effect of HCV genotype on the risk of cirrhosis and HCC in a Cox proportional hazards model adjusting for patients’ age, period of service (World War I/II, Vietnam era, post-Vietnam era), race, gender, HIV infection, alcohol use, diabetes, body mass index, and antiviral treatment receipt. Of the 110,484 patients with active HCV viremia, 88,348 (79.9%) had genotype 1, 13,077 (11.8%) genotype 2, 8337 (7.5%) genotype 3, and 1082 (0.9%) patients had genotype 4 infection. Despite being younger, patients with genotype 3 had a higher risk of developing cirrhosis (unadjusted hazard ratio, HR=1.40, 95% CI=1.32–1.50) and HCC (unadjusted HR=1.66, 95% CI=1.48–1.85) than HCV genotype 1 patients. After adjustment for pre-specified demographic, clinical, and antiviral treatment factors, the risk of cirrhosis and HCC was 31% (adjusted HR=1.31, 95% CI=1.22–1.39) and 80% (adjusted HR=1.80, 95%CI=1.61–2.03) higher in patients with genotype 3 compared to genotype 1 infected patients. Conclusion HCV genotype 3 is associated with a significantly increased risk of developing cirrhosis and HCC compared to HCV genotype 1. This association is independent of patients’ age, diabetes, body mass index, or antiviral treatment.

Background and Aims It has been reported that the incidence of intrahepatic cholangiocarcinoma (ICC) has increased in the USA, while extrahepatic cholangiocarcinoma (ECC) has decreased or remained stable. However, neither the recent trends nor the effects of the misclassification of Klatskin tumors are known. Methods Using the Surveillance, Epidemiology, and End Results program databases, we calculated the average annual age-adjusted incidence rates (AA-IRs) of ICC and ECC in 4-year time periods (1992–1995, 1996–1999, 2000–2003, 2004–2007). These AA-IRs were calculated with misclassified as well as correctly classified Klatskin tumors. AA-IRs were also calculated based on age, sex, and race. Multivariable Poisson regression models were used to evaluate the secular trends of ICC and ECC. Results The AA-IR of ICC was 0.92 in 1992–1995 and 0.93 in 2004–2007, while the AA-IR of ECC increased from 0.70 in 1992–1995 to 0.95 in 2004–2007. There was no significant trend in AA-IR of ICC (p = 0.07), while there was a significant increase in ECC across the 4-year time periods (p < 0.001). Klatskin tumors comprised 6.7 % of CCs with approximately 90 and 45 % misclassified as ICC during 1992–2000 and 2001–2007, respectively. Adjusted Poisson models showed no significant differences in the temporal trend of ICC or ECC due to misclassification of Klatskin tumors. Conclusions The incidence of ICC has remained stable between 1992 and 2007 with only slight fluctuations, while the incidence of ECC has been increasing. Misclassification of Klatskin tumors does not appear to play a significant role in the trends of CCs.