Serum angiogenic activity: diagnostic relevance in renal cell carcinoma

Angiogenesis is essential for tumor growth and progression. However, reported data on angiogenic parameters in patients with renal cell carcinoma are contradictory. The objective of this study was to use serum to compare the systemic angiogenic activity in patients with renal cell carcinoma and to determine if pathologic stage and grade correlated to this angiogenesis parameter.

Serum of 28 patients with a newly diagnosed renal cell carcinoma, 28 healthy volunteers and 9 patients with bladder carcinoma were used for this study. All sera were tested in a 72-hour endothelial cell proliferation assay. In addition the serum concentrations of the angiogenesis stimulators basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) were determined using standard ELISA assays.

The serum of renal cell carcinoma patients showed a median stimulation of human umbilical vein endothelial cells (HUVEC) of 89.79% (range 58.47-147.95%) and serum of healthy volunteers showed a median stimulation of 95.35% (range 74.64-141.77%) (p > 0.05). In contrast serum of patients with bladder carcinoma showed a median stimulation of 140.16% (range 64.82-200.16%) (p = 0.024). No correlations of the serum angiogenic activity and tumor stage or grade have been found in renal cell carcinoma patients. Furthermore, no correlations for serum bFGF and VEGF concentrations have been found.

Serum angiogenic activity of patients with renal cell carcinoma did not differ significantly from healthy controls, while serum of patients with bladder carcinoma showed a significant increase in endothelial cell stimulation. Furthermore, bFGF and VEGF serum concentrations did not correlate to serum angiogenic activity in patients with renal cell carcinoma. Therefore, the determination of systemic angiogenic parameters, in case of renal cell carcinoma, might not lead to adequate data concerning prognosis or therapeutic effects.