Soluble vascular endothelial growth factor receptor 2 (VEGFR2): New biomarker in advanced non-small cell lung cancer (NSCLC)?

Abstract

e22108 Background: An increase in VEGF expression in tumour or some blood compartments (i.e. serum or plasma) has been found in solid tumours of various origins. Several studies have suggested that ligands and receptors of the VEGFs/VEGFR system play an important role in tumour growth and is associated with metastasis and poor prognosis. The aim of our study was to investigate the usefulness of plasmatic VEGFR2 quantification as a new biomarker in advanced NSCLC. Methods: We studied 106 healthy controls (c) and 467 advanced NSCLC patients (p) (stage IIIB and IV) treated with cisplatin and docetaxel. Blood samples were collected before chemotherapy and the plasmatic levels of the VEGFR2 were determined by ELISA. Results: In the NSCLC group, the median age was 59.9, range (31–80); 82% were males. The histological subtypes were: 31.4% squamous, 49.8% adenocarcinoma, 15.3% large cell and undifferentiated and 3.5% other. There was a significant difference in the plasmatic levels of VEGFR2 between c and p (mean± SEM): 6318±152 ng/ml and 8141± 119 ng/ml, respectively (p<0.0001). On the other hand, we found no statistical differences according to sex, histology, or stage. The area under the ROC curve was 0.743 indicating that VEGFR2 is an adequate biomarker for the discrimination between c and p. Dividing the cohort in two subgroups according to VEGFR2 levels: high (>9473,9 ng/ml) and low (≤ 9473,9 ng/ml), we found significant difference in terms of Time to Progression (TTP). Patients with higher levels of VEGFR2 had a median TTP of 204 days whereas in the group with lower expression the median was 164 days, (p= 0.039). Conclusions: In advanced NSCLC, we found higher levels of soluble VEGFR2 in p than in c. There was a correlation between higher expressions of soluble VEGFR2 with better prognosis, in terms of TTP, therefore a more thorough understanding in the role of the plasmatic quantification of this angiogenic receptor in advanced NSCLC p seems to be an important task. No significant financial relationships to disclose.