NRAS and KRAS polymorphisms are not associated with hepatoblastoma susceptibility in Chinese children.

ABSTRACT

BACKGROUND: Hepatoblastoma is the most common hepatic malignancy in children, accounting for approximately 80% of all childhood liver tumors. KRAS and NRAS, members of the RAS gene family, are closely linked to tumorigenesis, and are frequently mutated in a variety of malignancies. They may thus play critical roles in tumorigenesis. However, there are few studies on the association between the RAS gene polymorphisms and risk of hepatoblastoma. METHODS: We investigated whether the polymorphisms at these genes are associated with hepatoblastoma susceptibility in a hospital-based study of 213 affected Chinese children and 958 cancer-free controls. Genotypes were determined by TaqMan assay, and association with hepatoblastoma risk was assessed based on odds ratios and 95% confidence intervals. RESULTS: No significant differences were observed between patients and controls in terms of age and gender frequency. All NRAS and KRAS genotypes are in Hardy-Weinberg equilibrium in the entire study population. We did not observe any significant association between hepatoblastoma risk and polymorphisms at NRAS and KRAS. The association between selected polymorphisms and hepatoblastoma risk was assessed after stratification by age, gender, and clinical stage. However, no significant association was observed even after stratification by age, gender, and clinical stage. CONCLUSIONS: The data suggest that NRAS and KRAS polymorphisms are irrelevant to hepatoblastoma susceptibility among Chinese population.