Morphologic analysis of microvessels in colorectal tumors with respect to the formation of liver metastases

Background and Objectives Overexpression of VEGF and proliferation of microvessels are strongly related to liver metastases, however, morphologic analyses of microvessels in liver metastases have not been reported. The purpose of the present study was to examine the correlation between liver metastases and the diameters of microvessel lumens in the tumor tissue. Methods Fifty‐nine patients with liver metastases from colorectal cancers and 112 patients who underwent curative colorectal resection and survived without any recurrence were reviewed. Microvessel density (MVD) and the diameters of the lumens of individual microvessels were assessed. Results There was a significant difference in terms of the mean MVD of primary tumors between patients with liver metastases and those without liver metastases. The numbers of patients with liver metastases who had microvessels 100–200 μm in diameter and microvessels more than 200 μm in diameter were significantly greater than patients without liver metastases. Microvessels with lumens more than 100 μm in diameter were not detected in the liver metastatic lesion. Conclusion Large microvessels in the primary tumor favor intravasation of cancer cells. J. Surg. Oncol. 2001;78:259–264. © 2001 Wiley‐Liss, Inc.