The frequency of tumor-infiltrating Tie-2-expressing monocytes in renal cell carcinoma: its relationship to angiogenesis and progression

Abstract

Objective: To examine the frequency of tumor-infiltrating Tie-2-expressing monocytes (TEMs) in renal cell carcinoma (RCC) and its association with microvessel density (MVD) and other clinical-pathologic features.

Materials and methods: This study enrolled 65 consecutive patients with RCC treated with radical nephrectomy. The frequency of tumor-infiltrating TEMs, which was defined as CD14(+) Tie-2(+) cells, was assessed using flow cytometry. MVD was measured by immunohistochemistry using anti-CD34 antibody. The association between clinicopathologic parameters, MVD, and the frequency of tumor-infiltrating TEMs in RCC was assessed.

Results: High frequency of tumor-infiltrating TEMs was significantly associated with advanced stage (P = .018), positive lymph nodes (P = .013), high grade (P = .019), and metastases (P = .006). Correlation analysis revealed that the frequency of TEMs was positively correlated with MVD.

Conclusion: Our findings revealed a significant association between prognostic tumor features, MVD, and the frequency of tumor-infiltrating TEMs in RCC and indicated that TEMs may play an important role in angiogenesis and progression of RCC.