Variations in the vascular endothelial growth factor pathway predict pulmonary complications

Abstract

Background: Clinical factors predicting pulmonary complications after lung resection have been well described, whereas the role of genetics is unknown. The vascular endothelial growth factor (VEGF) signaling pathway has been linked to acute lung injury. We hypothesized that genetic variations in this pathway may be associated with postoperative pulmonary complications after lung resection.

Methods: One hundred ninety-six single nucleotide polymorphisms (SNPs) in 17 genes in the VEGF pathway were genotyped in a discovery set of 264 patients and a replication set of 264 patients who underwent lobectomy for lung cancer. Multivariable analysis adjusting for baseline clinical factors was used to identify SNPs associated with pulmonary complications. Cumulative and classification and regression tree (CART) analyses were used to further stratify risk groups.

Results: The overall number of pulmonary complications was 164/528 (31%). The effects of 6 SNPs were consistent in the discovery and replication sets (pooled p value<0.05). The rs9319425 SNP in the VEGF receptor gene FLT1 resulted in a 1.50-fold increased risk (1.15-1.96; p=0.003). A cumulative effect for the number of risk genotypes and complications was also evident (p<0.01). Patients carrying 5 risk genotypes had a 5.76-fold increase in risk (2.73-12.16; p=4.44×10(-6)). Regression tree analysis identified potential gene-gene interactions between FLT1:rs9319425 and RAF1:rs713178. The addition of the 6 SNPs to the clinical model increased the area under the receiver operating characteristic curve by 6.8%.

Conclusions: Genetic variations in the VEGF pathway are associated with risk of pulmonary complications after lobectomy. This may offer insight into the underlying biological mechanisms of pulmonary complications.

Fig 1

Receiver operating characteristic curves for the ability to predict pulmonary complications with and without the genotype information. (AUC = area under the curve; SNP = single nucleotide polymorphism.)

Fig 2

Cumulative and classification and regression tree (CART) analysis of VEGF pathway genetic polymorphisms; p = 0.01. (CI = 95% confidence interval; OR = odds ratio; V = variant genotype; VEGF = vascular endothelial growth factor; WT = wild type.)