Tumour angiogenic activity and vascular survival ability in bladder carcinoma

Abstract

Background: Tumour angiogenic activity (TAA) is an important prognostic factor in many human tumours, including transitional cell carcinomas of the urinary bladder. The new tumour vessels are formed in the invading tumour front. This peripheral tumour area is internalised as soon as the growing tumour forms a new front.

Aims: To investigate and compare TAA with the ability of the tumour vasculature to survive (VSA) in inner tumour areas.

Methods: Fifty one cystectomy specimens with transitional cell carcinoma of the urinary bladder were studied. Sections were stained immunohistochemically for endothelial cells and proliferation activity, using the monoclonal antibodies CD31 and MIB-1, respectively. TAA was studied at the invading tumour edge—designated as the mean number of blood vessels in three “hot spots” at this site. VSA was assessed by comparing the vascular density in peripheral and inner tumour areas.

Results: High TAA at the invading tumour edge significantly correlated with lymph node involvement, but not with patient survival. Extensive lymphocytic infiltration was more frequent in tumours with high TAA. VSA was significantly higher in tumours of high proliferation index, high histological grade, advanced T stage, and poor prognosis. However, there was no association with metastasis to regional lymph nodes.

Conclusion: VSA and TAA provide a more complete profile of the tumour vasculature and are associated with aggressive tumour behaviour in transitional cell carcinomas of the urinary bladder. The qualitative information provided by VSA may be important for the identification of angiogenic tumours with differential responses to various antiangiogenic treatments.