Cancer and the Evolutionary Ecology of Invasions

This chapter examines cancer from the lens of invasion ecology. From cancer initiation to niche filling to tumor growth and then metastasis, the study of cancer has tight parallels to similar phenomena (speciation, adaptive radiation, range expansion, and invasive species biology) in nature. Each has access to conceptual and modeling frameworks, experimental techniques, technologies, and data that can inform the other. The growing appreciation that cancer evolves by natural selection in response to ecological forces within the tumor and to therapeutic interventions simply increases the opportunity and need for intellectual cross-fertilization. Cancer exemplifies ecological and evolutionary dynamics that can lead to the progressive evolution and diversification of cancer cell types within the patient. The scariest invasion of them all is transitioning to metastatic disease where the primary tumor has given rise to additional tumor burden in other organs of the body. Metastasis becomes the likely culmination of all the invasion processes that happen before, namely cancer initiation, diversification, and tumor growth. In recognition of these parallels, cancer biology and physicians are taking inspiration and concepts from ecology and evolution, such as invasion ecology. In turn, cancer biology also has much to offer the fields of ecology and evolution as tests and applications of broader principles and concepts, including those associated with biological invasions.