Association of Vascular Endothelial Growth Factor A (VEGFA) and its Receptor (VEGFR2) Gene Polymorphisms with Risk of Chronic Myeloid Leukemia and Influence on Clinical Outcome.

Introduction: Vascular endothelial growth factor A (VEGFA) and its kinase insert domain receptor (VEGFR2/KDR) were reported to be upregulated in chronic myeloid leukemia (CML); however, the influence of polymorphisms in VEGFA and VEGFR2 in CML pathogenesis and therapeutic response, have not yet been elucidated.
Methods: We aimed to analyze these polymorphisms in 212 CML patients and 212 healthy controls by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach.
Results: The VEGFA+936C>T polymorphism did not differ significantly between the CML patients and controls. The frequency of CT genotype was higher in CML patients than in controls (25 vs. 18%), higher in males than in females (29 vs. 18%), was more prevalent in the patients with splenomegaly (p = 0.03), and was negatively associated with lactate dehydrogenase (LDH) levels (p = 0.01). The frequency of VEGFR2 mutant T-allele was higher in CML patients than controls (p < 0.0001). In the dominant model, patients having the combined AT and TT genotypes were associated with 2.6-fold higher risk of CML [odds ratio (OR) = 2.6, 95% confidence interval (CI) = 1.71–3.97, p < 0.0001]. VEGFR2 AT genotype was significantly associated with high blast count (p = 0.006), minor hematological response (p = 0.03) and poor cytogenetic response (p = 0.003), indicating its role in therapeutic resistance. In contrast, poor molecular response was observed in patients with TT genotype (p = 0.02). VEGFA+936C>T polymorphism was found to have synergistic interaction with VEGFR2+1416A>T in inflating the risk for CML further (P(interaction) = 0.0002).
Conclusion: Our results indicate that VEGFR2+1416A>T polymorphism may be a useful marker in assessing the disease progression in CML patients. In addition, VEGFA+936C>T was observed to have additive effect in inflating the risk further.