A functional epidermal growth factor (EGF) polymorphism, EGF serum levels and renal cell carcinoma risk in a Chinese population.

The epidermal growth factor (EGF) gene encodes a growth factor that binds to the EGF receptor (EGFR), which is involved in activating pathways that promote cellular proliferation, survival, migration and differentiation, and lack of control is characteristic of malignant development. Previous studies showed that serum EGF levels may influence the risk of cancer. In this study, we genotyped the EGF G61A polymorphism (rs4444903) and measured serum EGF levels using an enzyme immunoassay in a hospital-based case-control study of 345 patients with diagnosed renal cell carcinoma (RCC) and 346 cancer-free controls in a Chinese population. Compared with the EGF 61GG genotype, the AA genotype had a significantly increased RCC risk (odds ratio=1.80, 95% confidence interval=1.04-3.12). Besides, the mean serum EGF levels in RCC patients (858.94+/-391.54 pg ml(-1)) were significantly lower than those in controls (1281.52+/-568.42 pg ml(-1), P<0.001). In addition, individuals carrying AA genotype had lower serum EGF levels than GA or GG carriers. These results suggested that the EGF G61A polymorphism is involved in the etiology of RCC and thus may be a marker for genetic susceptibility to RCC in Chinese populations. Larger studies are warranted to validate our findings.