Expression of vascular endothelial growth factor (VEGF) and its receptor FLK-1 in non-small cell lung cancer (NSCLC)--a preliminary report.

The assessment of tumour angiogenesis in NSCLC is presently a subject of intensive research with potential clinical applications. In this study, the expression of VEGF and FLK-1 was examined by immunohistochemistry in 67 archival tumour samples obtained from NSCLC patients treated by radical resection. Distribution of age, sex, tumour stage and histology was typical for patient population in Poland. VEGF expression (more than 25% of positive cells) was noted in 65% of tumour cells. FLK-1 expression was observed in 91% of tumour cells. Neither the number of positive cells nor the staining intensity correlated with the clinical variables (all p values >0.05, chi-square test). No correlation was noted between the expression of VEGF and FLK-1 (p=0.35, chi-square test). In survival analysis, neither the number of positive cells nor the staining intensity of both molecules was of prognostic significance. The expression of VEGF and FLK-1 in NSCLC cells was confirmed in this study. The relation to clinical variables and survival will be further assessed in a larger group of patients.