[Angiogenesis in bladder: prognosis indicator and therapeutic target]

Angiogenesis is a complex, multi-step process which leads to the formation of new blood capillaries (neovessels) from preexisting vessels. It is essential top the growth of solid tumours and tumour metastasis (tumour angiogenesis). This process is initiated by the synthesis, by tumour cells and non-malignant tumour-associated cells, of growth factors called antigenic factors or inducers. bFGF (basic Fibroblast Growth Factor) and VEGF (Vascular Endothelial Growth Factor) are the two angiogenic factors involved in bladder tumour angiogenesis. The angiogenic activity of a bladder tumour can be measured by the microvascular density (MVD), considered by some authors to be an independent prognostic indicator of recurrence and survival in the group of invasive bladder tumours. VEGF expression in bladder tumours and biological fluids (serum, urine) appears to be a predictive marker of the risk of progression of superficial bladder tumours. Urinary bFGF assay reveals high levels in patients with bladder tumour, but this elevation is not specific to bladder tumours. Inhibition of tumour angiogenesis has become a therapeutic target. Intravesical suramine and a fumagillin analogue (TNP-470) have given promising results in terms of efficacy and safety in the treatment of bladder tumours.