Collective behavior in cancer cell populations

In recent years the argument has been made that malignant tumors represent complex dynamic and self-organizing biosystems. Furthermore, there is increasing evidence that collective cell migration is common during invasion and metastasis of malignant tumors. Here, we argue that cancer systems may be capable of developing multicellular collective patterns that resemble evolved adaptive behavior known from other biological systems including collective sensing of environmental conditions and collective decision-making. We present a concept as to how these properties could arise in tumors and why the emergence of such swarm-like patterns would confer advantageous properties to the spatio-temporal expansion of tumors, and consequently, why understanding and ultimately targeting such collectivity should be of interest for basic and clinical cancer research alike.