Our bodies are composed of approximately 30 trillion cells that engage in a multitude of social behaviors that make us viable multicellular organisms including cells sharing resources, engaging in division of labor and working together to create and maintain the intracellular environment. Natural selection acts on these and other behaviors of cells in the body, including controlled cell death and proliferation controls, in ways that can lead to cancer initiation and progression. All of this occurs within a complex and dynamic ecological environment that shapes resource availability and hence the selection pressures that cells face during neoplastic progression. In this talk I describe how cancer can be understood as cheating in multicellular cooperation and show results from computational models that suggest that cellular cheating through resource monopolization may be an important contributor to the evolution of invasion and metastasis.