Genetic polymorphisms of VEGF, interactions with cigarette smoking exposure and esophageal adenocarcinoma risk

Abstract

Vascular endothelial growth factor (VEGF) is a major regulator of angiogenesis in the process of tumor growth and metastasis in esophageal adenocarcinoma (EA). Polymorphisms in the VEGF gene have been associated with altered VEGF expression and plasma VEGF levels. We hypothesized that polymorphisms of VEGF may contribute to EA risk. Functional polymorphisms in the VEGF gene (-460C/T, +405C/G and +936C/T) were determined in 308 patients with EA and 546 healthy controls. Logistic regression analysis was employed to assess the associations between genotypes, haplotypes of VEGF and EA risk, adjusting for multiple confounding factors. Compared with the +936CC genotype, the combined +936CT+TT genotypes were significantly associated with increased risk of developing EA, with adjusted odds ratio (OR) = 1.49 [95% confidence interval (CI), 1.05-2.12; P = 0.027]. The -460CT+CC were associated with increased risk of EA in smokers (adjusted OR = 1.57; 95% CI, 1.07-2.30; P = 0.021), whereas the -460CT/CC were associated with decreased risk of EA (adjusted OR = 0.47; 95% CI, 0.25-0.91; P = 0.025) in non-smokers. Compared with non-smokers with the +460TT, smokers with the +460CT+CC had significantly higher risk of EA (adjusted OR = 3.32; 95% CI, 1.56-7.10; P = 0.002). No overall or interacting association with EA risk was found for the +405C/G polymorphism. Haplotype CGT (-460C/+405G/+936T) was significantly associated with higher risk of EA (adjusted OR = 1.70; 95% CI, 1.04-2.73; P = 0.034). These results suggested that cigarette smoking modifies the association between VEGF polymorphisms and EA risk among Caucasians.

Fig. 1.

The ORs of smoking and VEGF–460C/T interaction for the development of EA at different categories of pack-years. Category 1 = pack-years ≤1; Category 2 = pack-years 1–20; Category 3 = pack-years 20–50 and Category 4 = pack-years >50.