Microvessel quantification and its possible relation with liver metastasis in colorectal cancer

BACKGROUND. Several studies have proven the usefulness of microvessel quantification as a prognostic factor for patients with various malignant tumors. The aim of this paper was to clarify the relationship between microvessel density (MVD) as a parameter of tumor angiogenesis and liver metastasis in colorectal cancer. METHODS. A total of 175 patients with advanced colorectal cancer were evaluated (58 with concurrent liver metastasis). Microvessel quantification was performed immunohistochemically, using monoclonal antibodies against endothelial protein Factor VIII-related antigen (F8RA) and against endothelial surface marker CD34. Finally, the relationship between MVD and liver metastasis was analyzed. RESULTS. A significant correlation was observed between MVD for F8RA and MVD for CD34 (n = 175, r = 0.9560, P = 0.0001). MVD in the tumors stained for F8RA ranged from 15.2 to 78.6 microvessels per X 200 field (mean 32.8 ± 11.7), while the tumors stained for CD34 varied between 21.6 and 118.8 microvessels per x 200 field (means 56.1 ± 20.5). A significantly higher MVD was observed in the tumors with liver metastatic disease compared with the tumors without liver metastasis (F8RA: mean 36.1 ± 11.3 vs. 31.2 ± 11.5, P = 0.0090; CD34: mean 64.4 ± 20.4 vs. 52.0 ± 19.4, P = 0.0010). CONCLUSIONS. Microvessel quantification within a colorectal tumor using immunohistochemical staining methods has shown a significant correlation between MVD and liver metastasis. Tumors with a greater MVD may thus have a greater hematogenous metastatic propensity.