Tracing the origins of metastasis

Cancer metastasis is often considered an orderly sequence of events leading to the colonization of distal organs by malignant cells. In fact, the evolution of metastatic disease is a dynamic process that is influenced by unique cellular lineages, altered microenvironments, distinct anatomical restrictions and multiple genetic and epigenetic alterations. These factors all contribute to variable clinical courses, likely requiring tailored therapy. As we inch closer towards personalized medicine, there is a renewed conceptual and technological focus on characterizing the cellular and genetic heterogeneity within tumours, to ultimately trace the origins of metastatic cells in different cancers.