Correlation between VEGFR2-V297I gene polymorphism and bevacizumab combined with whole brain radiotherapy for non-small cell lung cancer patients with brain metastasis

Objective To investigate the effect of VEGFR2-V297I gene polymorphism on the efficacy and its correlation with bevacizumab combined with whole brain radiotherapy in non-small cell lung cancer (NSCLC) patients with brain metastasis. Methods A total of 141 advanced NSCLC patients with brain metastasis who were admitted to Hanzhong Central Hospital from June 2015 to June 2017 and received bevacizumab combined with whole brain radiotherapy were collected. Their sex, age, pathological type, ECOG score, EGFR mutant and survival data were recorded. After bevacizumab combined with whole brain radiotherapy, the progress and survival of patients with different VEGFR2-V297I genotypes were compared. Results Among the 141 patients with gastric cancer, there were 83 patients (58.87%) with CC genotype, 49 patients (34.75%) with CT genotype, and 9 patients (6.38%) with TT genotype, which was consistent with Hardy-Weinberg Law of equilibrium (χ²=0.21, P=0.90). For evaluation of recent curative effects, the objective response rates of patients with CC and CT/TT genotype were 48.19% and 48.28%, respectively, and the disease control rates were 89.16% and 91.38%, respectively, without statistical difference (P>0.05). The median progress free survival (PFS) for CC genotype carriers was 9.012 months (95% CI: 8.260—9.764), and the median PFS for patients with CT/TT genotype carriers was 6.741 months (95% CI:5.787—7.695) (Log-rank=10.240, P=0.001). The median OS for CC genotype carriers was 19.236 months (95% CI:18.176—20.295), and the median OS for CT/TT genotype carriers was 17.285 months (95% CI:16.175—18.395) (Log-rank=5.456, P=0.02). According to the Cox proportional hazard regression model, age, sex, ECOG score, and VEGFR2-V297I locus were independent risk factors affecting PFS in patients. Conclusions VEGFR2-V297I gene polymorphism can affect the efficacy of bevacizumab combined with whole brain radiotherapy in NSCLC patients with brain metastasis.CT/TT genotype is an independent risk factor for its progression and death.