Beata Ujvari

Centre for Integrative Ecology

Deakin University

 

Transmissible cancers constitute an example of cancer evolution par excellence: processes akin to Darwinian selection drive individual cancer cells along evolutionary landscapes culminating in resistant, invasive, and ultimately immortal cancer phenotypes.  The fitness of transmissible cancer cells undeniably surpasses those remaining within, and hence succumbing with their single host.  In spite of the clear advantage of transmissibility, communicable (non-parasitic) cancers are surprisingly rare.  We propose that transmissible cancers are subjected to similar evolutionary processes facilitating exotic species to invade and colonize novel habitats.  Therefore we examine the properties of both tumor cells and host organisms that permit transmission.  In conclusion, we find that both at organismal and ecosystem levels, very few species and cancers become invasive.  We propose that successful transmission of cancer requires a “perfect storm” with the rare confluence of multiple host and tumor cell traits.  However, understanding the necessary and sufficient conditions for cancer transmission between hosts permits novel insights into the evolutionary dynamics that both promote and constrain tumor growth.