The experimental studies in vitro and in vivo were performed to investigate the effects of carcinostatic agents in the adhesion of cancer cells to endothelial cells. Certain carcinostatic agents induce the expression of E-selectin on endothelial cells and enhance the expression of carbohydrate ligands on cancer cells. Consequently, increased adhesion of cancer cells to endothelial cells was observed by the treatment of carcinostatic agents. In the trans-splenic hepatic metastasis model using nude mice, the augmentation of cancer metastasis was observed by the treatment of carcinostatic agents. From the above, we concluded that carcinostatic agents may increase the metastatic ability of cancer cells in patients with cancer.