Purpose: The vascular endothelial growth factors (VEGF-A, -C, -D) and the VEGF receptors (VEGFR-1, -2, and -3) are important molecular markers in angiogenesis and lymphangiogenesis. This study elucidates the prognostic significance of these molecular markers in tumor cells as well as in the tumor stroma of resected non-small cell lung cancer tumors.
Experimental design: Tumor tissue samples from 335 resected patients with stage I to IIIA disease were obtained and tissue microarrays were constructed from duplicate cores of tumor cells and surrounding stromal tissue from each resected specimen. Immunohistochemistry was used to evaluate the expression of each molecular marker. Microvessel density was assessed by CD34 immunohistochemical staining.
Results: In univariate analyses, high tumor cell expression of VEGF-A (P = 0.0005), VEGFR-1 (P = 0.013), VEGFR-2 (P = 0.006), and VEGFR-3 (P = 0.0003) were negative prognostic indicators for disease-specific survival (DSS). In tumor stroma, however, high expression of VEGF-A (P = 0.017), VEGF-C (P = 0.003), VEGF-D (P = 0.009), VEGFR-1 (P = 0.01), and VEGFR-2 (P = 0.019) correlated with good prognosis. There was no significant correlation between microvessel density and DSS. In multivariate analyses, high expression in tumor cells of VEGFR-3 (P = 0.007) was an independent negative prognostic factor for DSS, whereas in stromal cells, high VEGF-C (P = 0.004) expression had an independent positive survival impact.
Conclusion: These are the first tissue microarray data in non-small cell lung cancers showing a positive prognostic impact by highly expressed angiogenic markers in tumor stroma, with VEGF-C as a major independent prognostic indicator.