Microvascular density, macrophages, and mast cells in human clear cell renal carcinoma with and without bevacizumab treatment.

Clear cell renal cell carcinoma (ccRCC) represents a highly vascularized aggressive kidney cancer. Due to ccRCC chemotherapy resistance, antiangiogenesis is one of the most innovative targeted therapies for this tumor. The tumor microenvironment exerts important roles in tumor growth, angiogenesis, and metastatic escape.

In this study, we investigated the composition of tumor cell microenvironment including mast cells, macrophages, and microvascular density in ccRCC tumor tissues collected from patients who underwent nephrectomy treated or not with bevacizumab as neoadjuvant therapy before surgery.

The results of this study indicate that bevacizumab-treated ccRCC samples present reduced microvascular density as well as a lower number of CD68-positive macrophages and tryptase-positive mast cells in comparison with the untreated patients.

It follows that the antiangiogenic activity of bevacizumab may be due to a direct effect on angiogenic cytokines released by tumor cells and an indirect effect on the release of pro-angiogenic factors by inflammatory stromal cells.

Urologic oncology. 2019 Feb 06 [Epub ahead of print]

Roberto Tamma, Monica Rutigliano, Giuseppe Lucarelli, Tiziana Annese, Simona Ruggieri, Eliano Cascardi, Anna Napoli, Michele Battaglia, Domenico Ribatti

Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, Bari, Italy., Department of Emergency and Organ Transplantation-Urology, Andrology and Kidney Transplantation Unit, University of Bari Medical School, Bari, Italy., Department of Emergency and Organ Transplantation-Section of Pathology, University of Bari Medical School, Bari, Italy., Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari Medical School, Bari, Italy. Electronic address: .