Large-scale Real-time Reverse Transcription-PCR Approach of Angiogenic Pathways in Human Transitional Cell Carcinoma of the Bladder: Identification of VEGFA as a Major Independent Prognostic Marker

Abstract

Actors of the angiogenesis pathways are targets for the new promising targeted therapies already used in several malignancies. In bladder cancer, antiangiogenic molecules could also add to already existing treatment options. To evaluate the involvement of angiogenesis pathways in bladder carcinogenesis and identify new molecular markers having a clinical implication. Expression levels of 40 genes involved in angiogenesis were assessed by quantitative real time RT-PCR in 157 urothelial tumour bladder samples obtained from patients who underwent transurethral bladder resection or radical cystectomy between 2001 and 2005. Pathologic tumour staging showed: 73 non-muscle-invasive bladder tumours (30 low-grade pTa, 14 high-grade pTa, and 29 high-grade pT1), and 84 muscle-invasive tumours (> or = pT2), all of high grade. RT-PCR results were associated with a survival analysis. VEGFA, MET, CXCR4, and IL8 were significantly overexpressed in tumour samples as compared to normal bladder tissue. VEGFA overexpressions were found in 89% of non-muscle-invasive and 66% of muscle-invasive tumour samples. In univariate analysis, for invasive tumours, VEGFA overexpression was associated with a poorer outcome in both overall and disease-free survival (p=0.011 and 0.026 respectively) at a 13-mo median follow-up. Multivariate analysis retained T stage, N status, and VEGFA overexpression as independent prognostic factors in both overall and disease-free survival (p=0.02 and p=0.04, respectively, for VEGFA). This study shows that, in bladder cancer, VEGFA status could be used as a prognostic factor at the individual level. VEGFA overexpression could guide a rationalized use of the costly antiangiogenic therapies which could therefore become part of the treatment options in bladder cancer.