A functional polymorphism in the epidermal growth factor gene is associated with risk for hepatocellular carcinoma

Abstract

Background & aims: A single nucleotide polymorphism 61*G (rs4444903) in the epidermal growth factor (EGF) gene has been associated, in 2 case-control studies, with hepatocellular carcinoma (HCC). We tested associations between demographic, clinical, and genetic data and development of HCC, and developed a simple predictive model in a cohort of patients with chronic hepatitis C and advanced fibrosis.

Methods: Black and white subjects from the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) trial (n=816) were followed up prospectively for development of a definite or presumed case of HCC for a median time period of 6.1 years. We used the Cox proportional hazards regression model to determine the hazard ratio for risk of HCC and to develop prediction models.

Results: Subjects with EGF genotype G/G had a higher adjusted risk for HCC than those with genotype A/A (hazard ratio, 2.10; 95% confidence interval, 1.05-4.23; P=.03). After adjusting for EGF genotype, blacks had no increased risk of HCC risk compared with whites. Higher serum levels of EGF were observed among subjects with at least one G allele (P=.08); the subset of subjects with EGF G/G genotype and above-median serum levels of EGF had the highest risk of HCC. We developed a simple prediction model that included the EGF genotype to identify patients at low, intermediate, and high risk for HCC; 6-year cumulative HCC incidences were 2.3%, 10.4%, and 26%, respectively.

Conclusions: We associated the EGF genotype G/G with increased risk for HCC; differences in its frequency among black and white subjects might account for differences in HCC incidence between these groups. We developed a model that incorporates EGF genotype and demographic and clinical variables to identify patients at low, intermediate, and high risk for HCC.

Figure 1

Portion of subjects developing HCC among four different subgroups defined by EGF genotype and serum protein levels above or below the median.

Figure 2

Kaplan–Meier estimates of 6-year cumulative incidence of HCC among subjects predicted to have low (<2% incidence), intermediate (2-8% incidence), and high (>8% incidence) risk of HCC according to regression Model 2.