Background: It is well known that vascular endothelial growth factor (VEGF) and its receptors are closely related to tumor angiogenesis, but the exact relationship with patients' prognosis is unclear till now. The aim of this study is to explore the expression of VEGF and its receptors KDR, Flt1 in pulmonary carcinoma and their relationship with patients' prognosis.
Methods: The expression of VEGF, KDR and Flt1 was examined immunohistochemically by PV-9000 method in 75 cases of pulmonary carcinoma with complete follow-up records.
Results: There was an extensive expression of VEGF, KDR and Flt1, mainly in the cytoplasm of tumor cells (TCs), fibroblasts (FBs), and endothelial cells. The distribution of VEGF, KDR and Flt1 was heterogeneous, mainly located at periphery of the tumor mass or necrosis. The positive rate of VEGF, KDR and Flt1 in the TCs was all significantly higher than that in the FBs (P < 0.01, P < 0.02, P < 0.02). Both in TCs and FBs, the positive expression of VEGF, KDR and Flt1 was related to the postoperative survival of patients (P < 0.01, P < 0.01, P < 0.01; P < 0.01, P < 0.01, P < 0.05). The survival time in patients with positive VEGF, KDR or Flt-1 in TCs was significantly lower than that in those with corresponding negative one respectively (P < 0.0001, P < 0.0005, P < 0.0005). There was a positive correlation between VEGF and Flt1 in TCs (P < 0.01), between VEGF in FBs and Flt1 in TCs (P < 0.01), and also between VEGF and KDR or Flt1 in FBs (P < 0.01, P < 0.01).
Conclusions: VEGF may act as a considerable promoting growth factor on tumor cells via Flt1, mainly in autocrine and less in paracrine manner. VEGF, KDR and Flt1 may exert important roles in prognosis of patients with pulmonary carcinoma.