Role of tumor-associated macrophages in relation to angiogenesis in urothelial bladder carcinoma

Background: Urothelial Bladder carcinoma is an aggressive tumor with male predominance. The tumor microenvironment is found to affect tumor progression and biology. One of its main constituents is tumor-associated- macrophages (TAMs). Angiogenesis is a powerful factor in the development of many tumors and is supposed to be induced by tumor cells and some stromal components that regulate tumor behavior. Aim: To assess the correlation of TAMs and angiogenesis in the stroma of urothelial carcinoma and its correlation with the tumor grade and stage and nodal metastasis. Material and Methods: This study was carried out on 30 paraffin blocks of bladder urothelial carcinoma. Hematoxylin and eosin staining was done for confirmation of the histopathological diagnosis. Immunohistochemical staining by CD68 antibody was done for counting of TAMs and CD34 antibodies for tumor-associated angiogenesis (microvessel count). Results: Significant higher TAMs count was detected in high-grade and invasive bladder cancers compared to low-grade and non-invasive types and in patients with nodal metastasis. Moreover, microvessel counts (MVCs) were significantly higher in higher grade, invasive bladder cancers and in patients with nodal metastasis. There was a positive correlation between the predominance of CD68+ TAMs and CD34+ MVCs in urothelial carcinoma. Conclusion: There is a positive correlation between TAMs and angiogenesis in the stroma of urothelial carcinoma and both are positively correlated with tumor grade, stage, and nodal metastasis. Our data indicated that both TAMs and MVCs could serve as prognostic markers for urothelial bladder cancer.