Populations of cancer cells are subject to the same core evolutionary processes as asexually reproducing, unicellular organisms. Transmissible cancers are particularly striking examples of these processes. These unusual cancers are clonal lineages that can spread through populations via physical transfer of living cancer cells from one host individual to another, and they have achieved long-term success in the colonization of at least eight different host species. Population genetic theory provides a useful framework for understanding the shift from a multicellular sexual animal into a unicellular asexual clone and its long-term effects on the genomes of these cancers. In this Review, we consider recent findings from transmissible cancer research with the goals of developing an evolutionarily informed perspective on transmissible cancers, examining possible implications for their long-term fate and identifying areas for future research on these exceptional lineages.

癌细胞群经历与无性繁殖的单细胞生物相同的核心进化过程。传染性癌症是这些过程中特别引人注目的例子。这些不寻常的癌症是克隆谱系，可以通过将活癌细胞从一个宿主个体物理转移到另一个宿主个体来在群体中传播，并且它们在至少八种不同宿主物种的定殖中取得了长期成功。群体遗传学理论为理解从多细胞有性动物到单细胞无性克隆的转变及其对这些癌症基因组的长期影响提供了一个有用的框架。在这篇综述中，我们考虑了传染性癌症研究的最新发现，目标是对传染性癌症形成一种进化视角，研究对其长期命运的可能影响，并确定这些特殊谱系的未来研究领域。