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

Association between the epidermal growth factor rs4444903 G/G genotype and advanced fibrosis at a young age in chronic hepatitis C

BACKGROUND

The epidermal growth factor (EGF) rs4444903 A>G polymorphism has been associated with the development of liver cancer, which commonly complicates cirrhosis of viral origin; however, whether this polymorphism might be associated with fibrosis progression in chronic viral hepatitis is unknown. The present study was performed to assess the allelic and genotypic frequencies of the rs4444903 A>G polymorphism in patients with chronic hepatitis C virus HCV infection and to ascertain whether this polymorphism might be an independent predictor of the degree of fibrosis.

METHODS

An RFLP-PCR technique was used to genotype 645 patients (211 with cirrhosis); 528 were referred for the diagnosis and treatment of chronic hepatitis C, and 117 were transplanted for HCV-related end stage liver disease. A group of 428 healthy subjects served as a control. All the subjects were of Caucasian ethnicity.

RESULTS

The EGF rs4444903 A>G polymorphism genotype frequencies in HCV chronic infected patients were as follows: A/A=227 (35.3%), A/G=328 (50.9%), and G/G=90 (14.8%). Genotype frequencies were found to differ between patients with an Ishak staging score⩽2 (A/A=117, A/G=157, G/G=34) and patients with a score>2 (A/A=110, A/G=171, G/G=56, p=0.038). A highly significant linear relationship between increasing stage scores and EGF genotype was detected in younger patients (A/A: 2.02±0.18, A/G: 2.55±0.17, G/G: 3.00±0.32, p=0.008). However, no significant association was detected between the stage score and EGF genotype in older patients (A/A: 3.79±0.19, A/G: 3.64±0.15, G/G: 3.98±0.30 p=0.579).

CONCLUSIONS

The EGF rs4444903 A>G polymorphism may facilitate liver fibrosis progression in Caucasian patients with chronic hepatitis C, especially in younger patients.

A functional polymorphism in the epidermal growth factor gene is associated with risk for glioma in a Chinese population

Epidermal growth factor (EGF) plays a key role in survival of neural and glial precursor cells. A single nucleotide polymorphism of the EGF gene +61G/A in the 5'-untranslated region has been reported to be associated with susceptibility to glioma. The purpose of this study was to investigate the potential association between EGF +61G/A and brain glioma in a Chinese population. A case-control study involving 180 patients with glioma and 360 controls was done. Polymerase chain reaction restriction fragment-length polymorphism assay was used to analyze the EGF +61G/A genotypes. Patients with glioma had a significantly higher frequency of AA genotype (odds ratio, 2.25; 95% confidence interval, 1.20, 4.21; p=0.01] than controls. When stratified by histologic features and World Health Organization grade of glioma, distribution of each genotype did not significantly differ. Our data suggested that the EGF +61G AA genotype was associated with a higher glioma risk in a Chinese population. This finding is in contrast with previous studies that reported the G allele as a risk factor for glioma in white patients.

Meta-analysis of epidermal growth factor polymorphisms and cancer risk: involving 9,779 cases and 15,932 controls

The epidermal growth factor (EGF) pathway stimulates proliferation and differentiation of epidermal and epithelial tissues, and plays an important role in tumorigenesis. The association between EGF polymorphisms and cancer risk is controversial; thus, we performed this meta-analysis. Overall, 41 case-control studies with 9,779 cases and 15,932 controls were retrieved. We found that EGF +61A/G polymorphism increased overall cancer risk (G allele vs. A allele: OR=1.181, 95% CI=1.077-1.295, P(heterogeneity) < 0.001; GG vs. AA: OR=1.370, 95% CI=1.143-1.641, P(heterogeneity) < 0.001; GG+GA vs. AA: OR=1.175, 95% CI=1.047-1.318, P(heterogeneity) < 0.001). In the stratified analysis by cancer type, the +61 G allele was a risk factor for colorectal cancer, esophageal carcinoma, gastric cancer, and hepatocellular carcinoma. Individuals who carried +61G allele had higher cancer susceptibility in mixed and European racial subgroups. An increased association was detected in the hospital-based subgroup. No significant association was found among EGF -1380A/G, -1744G/A, rs6983267T/G polymorphisms and cancer risk.