Metastasis is a process of cell migration that can be collective and guided by chemical cues. Viewing metastasis in this way, as a physical phenomenon, allows one to draw upon insights from other studies of collective sensing and migration in cell biology. Here we review recent progress in the study of cell sensing and migration as collective phenomena, including in the context of metastatic cells. We describe simple physical models that yield the limits to the precision of cell sensing, and we review experimental evidence that cells operate near these limits. Models of collective migration are surveyed in order to understand how collective metastatic invasion can occur. We conclude by contrasting cells' sensory abilities with their sensitivity to drugs and suggesting potential alternatives to cell-death-based cancer therapies.
Keywords: cell migration; collective behavior; gradient sensing; metastasis.