Clinicopathological impact of VEGFR2 and VEGF‐C in patients with EGFR ‐major mutant NSCLC receiving osimertinib

BACKGROUND: Vascular endothelial growth factor (VEGF) has been identified as one of the resistant mechanisms to epidermal growth factor receptor‐tyrosine kinase inhibitors (EGFR‐TKIs). However, the relationship between the efficacy of osimertinib and protein expression of VEGF family members in patients with advanced non‐small cell lung cancer (NSCLC) harboring EGFR mutations remains unclear. METHODS: A total of 76 patients with advanced NSCLC with EGFR major mutations (del19 or L858R) receiving first‐line osimertinib were eligible as the osimertinib (Osi) group, whereas 43 patients receiving first‐ or second‐generation EGFR‐TKIs were compared with the control group. The expression of vascular endothelial growth factor receptor 2 (VEGFR2) and vascular endothelial growth factor C (VEGF‐C) in the tumor specimens was analyzed using immunohistochemistry. RESULTS: VEGFR2 and VEGF‐C were highly expressed in 65.8% and 51.3% of patients, respectively, in the Osi group, and 69.7% and 76.7%, respectively, in the control group. High VEGFR2 and VEGF‐C levels were significantly associated with poor performance status (PS) and female sex, respectively. In the Osi group, patients with co‐high expression of VEGFR2 and VEGF‐C showed significantly worse progression‐free survival (PFS) and overall survival (OS) than those without co‐high expression. In del19, VEGFR2 was a significant predictor of PFS and OS and independent predictor of OS in multivariate analysis. In L858R, co‐high expression of VEGFR2 and VEGF‐C was identified as a significant predictor of PFS and OS and independent predictor of PFS. CONCLUSION: VEGFR2 and VEGF‐C are highly expressed in EGFR‐mutant NSCLC cells. Increased expression of VEGFR2 was identified as a significant prognostic factor in patients with EGFR del19 mutation who received osimertinib, whereas co‐high expression of VEGFR2 and VEGF‐C was a significant predictor for those with EGFR L858R mutation.