Fibrolamellar hepatocellular carcinoma versus conventional hepatocellular carcinoma: Better 5-year survival or artifactual result of research methodology?

摘要

Among the primary hepatic malignant tumours, hepatocellular carcinoma (HCC) is the most common, while fibrolamellar carcinoma is a rare variant of HCC. In a recent article by Eggert et al examining the epidemiology of fibrolamellar hepatocellular carcinoma (fHCC) in the USA from 2000 to 2010,1 the authors reported better 5-year survival for fHCC compared with conventional HCC similar to previous studies. Even though several previous studies have advocated that fHCC is less aggressive than conventional HCC, some recent studies have failed to confirm the observation of a better outcome in fHCC.8"11 Cirrhosis is a well established poor prognostic factor in HCC. Since fHCC almost always arises in non-cirrhotic liver, the apparent better outcome in fHCC may be related to lack of cirrhosis. With the aim of providing more epidemiological evidence on the disparities in 5-year survival between fHCC and conventional HCC, we carried out a comparative meta-analysis and meta-regression. A meta-regression analysis is a type of statistical analysis that quantitatively explores interactions between a given effect (eg, the 5-year survival of fHCC vs conventional HCC in patients as expressed with ORs) and a moderator or covariate of interest (eg, prevalence of cirrhosis in each study).