Evolution and cancer

Evolution is the process by which living organisms change through time, and natural selection is the process which leads some organisms to thrive and others to die out. Evolutionary medicine tries to explain why traits leading to susceptibility to disease get maintained or even positively selected. Cancer, being a genetic disease, can be analysed as an example of evolution by natural selection. The observation that humans in developed societies have much higher rates of cancer can be analysed and explained by an evolutionary approach. At a cellular level, tumours are made up by a population of cells continuously growing and mutating while interacting with the microenvironment of the body. Thus, the mechanism of changes in individual tumours is the process of natural selection. Evolutionary biology is now increasingly used to better understand tumour growth and therefore to improve treatments.