Angiostatic activity of anticancer agents in the chick embryo chorioallantoic membrane (CHE-CAM) assay.

Most anticancer agents are screened for antiproliferative and differentiation-inducing activity on tumor cells, but not for differential effects on vascular endothelium. Clinically active cytotoxic or cytostatic agents and selected analogs were tested in a closed, ethically accepted and inexpensive in vivo fertilized egg system [CHE-CAM]. The results revealed characteristic effects on vessel numbers between day 7 and 11 and on embryo weight at day 12. Hitherto unknown angiostatic activities were discovered with antitumor antibiotics, plant alkaloids, antimetabolites and other classes of compounds. The information provided by the CHE-CAM assay could represent a valuable complementation to the existing drug-screening systems for solid tumors and suggests a selective angiostatic role of some antitumor agents currently used in combination treatments.