Qualitative and Quantitative Analysis of Angiogenetic Factors in Transitional Cell Bladder Carcinoma: Relationship with Clinical Course at 10 Years Follow-up

Many authors have shown that tumor hypoxia exerts its own influence on malignant progression by inducing angiogenetic factors and new blood vessels inside and around the tumor. This event usually suggests a poor prognosis and/or aggressive tumor behavior. The objective of the present study is to compare molecular analysis of angiogenetic factors with microvessel density (MVD) in bladder carcinoma. Twenty-nine consecutive patients underwent transurethral or open surgery for bladder tumors. Neoplastic tissue samples, normal-appearing bladder mucosa and blood samples were taken from each patient. All the tissues underwent mRNA extraction and Northern blot analysis, marked with specific probes for inducible nitric oxide sinthase (iNOS), cyclo-oxygenase-2 (cox-2), vascular endothelial growth factor (VEGF) and were evaluated by gel-electrophoresis. Microvessel density, a quantitative analysis for neoangiogenesis, was also evaluated by using CD31 immunohistochemical assay and compared with both molecular analysis and patient follow-up. Two follow-up for recurrence and/or progression were performed at 74 months and 10 years from surgery respectively. Pathological evaluation demonstrated the presence of superficial transitional cell carcinoma (sTCC) in 15 patients, while 14 had an invasive bladder tumor (iBT). At both 74 months and 10 years follow-up, all patients with lower MVD had a shorter survival time. No significant results were obtained by comparing disease progression or survival rate with VEGF, iNOS and COX-2 levels. A proportional increase of VEGF expression and MVD compared with poor prognosis was the expected outcome of our study. These results were disregarded at both the 1st and the 2nd follow-up. A strong association between MVD>20 and survival rate was noted both in sTCC (p=0.024) and iBT (p>0.001) patients. These results confirm that MVD could be considered a good prognostic factor. The angiogenetic cytokines overexpression found in control tissue samples of sTCC could have clinical significance, either as a macroscopically unidentified diffuse carcinogenetic process or the presence of a systemic immune-response against tumor cells.