First, according to the reading by Aktipis and Nesse - Evolutionary foundations for Cancer biology; they use ecology theories and methods for understanding why we are vulnerable to cancer. There are six types of evolutionary explanations for traits that leave organisms vulnerable to disease; Mismatch with novel environments, Co-evolution with fast evolving pathogens, Constraints on what selection can do, and the Trade-offs, Reproductive successes, and defenses with costs as well as benefits.
Next, the life of a cell is affected by various threats and opportunities (predatory immune cells), limited growth factors, oxygen, glucose, physical constraints, adjacent cells, and membranes in which they are attached. In addition, the normal micro-environment of cells and aggression and stress plays a critical role in cancer susceptibility. Therefore, changes to micro-environments are key factors in how cancer is initiated, progressed, and responds to treatments.
Finally, normal cells do not become malignant due to race, gender, or class. Malignant tumors evolve from genetic instabilities and mutator phenotypes. Moreover, changes to neighboring cells can enhance the growth of cancer cells, and bacterial and inflammation damages tissues and makes them more vulnerable to cancers. The importance of an evolutionary understanding of cancer comes from how it progresses (somatic evolution), how cancer cells interact with environments (ecological approaches), why it is not more common (natural selection for cancer suppression mechanisms), and why cancer suppression mechanisms can never be perfect (constraints, trade offs, and other evolutionary reasons for vulnerability to diseases).