Figure 10.1 Schematic of the metastatic cascade. (a) Invasion of cancer cells through the extracellular matrix. (b) Intravasation of cancer cells into the circulatory system. (c) Circulating tumor cells (CTCs). (d) Platelet aggregation promotes adhesion of CTCs to endothelium. (e) Extravasation of cancer cells into distal sites. (f) Cancer cells colonize distal sites, forming metastases.