Estimation of angiogenesis with anti-CD 105 immunostaining in the process of colorectal cancer development

Background. The expression of panendothelial markers (eg, CD34, CD31, and factor VIII) is not always observed in angiogenic vessels, and such markers are not useful for measuring angiogenesis. In contrast, CD105 is preferentially expressed in angiogenic vessels and thus may be valuable for measuring angiogenesis. We hypothesized that microvessel quantification by means of CD105 might be useful for measuring angiogenesis in the colorectal adenoma-carcinoma sequence. Methods. We immunohistochemically investigated 54 cases of colorectal adenomas and 20 cases of carcinomas using monoclonal antibodies CD34 and CD105, and microvessel density (MVD) was counted at ×200 magnification. Results. Microvessels positive for CD34 were distributed almost uniformly in adenomas. In contrast, microvessels positive for CD105 were preferentially observed in the surface area of adenomas. In carcinomas, CD34 stained only a proportion of blood vessels that were positive for CD105. No significant difference of MVD for CD34 was observed in the colorectal adenoma-carcinoma sequence. In contrast, an increment of MVD for CD105 from low-grade to high-grade dysplasia (P < .0001) and that from high-grade dysplasia to carcinomas (P < .05) was statistically significant. Conclusions. Assessing neovascularization with CD105 in the process of colorectal cancer development may thus be a valuable marker for predicting the risk of colorectal cancer development.