Cancer Immunoediting and Hijacking of the Immune System

In this chapter we present an historic perspective of the relationship between cancer and the immune system. We will see how it was not always clear that the immune system was able to recognize and fight cancer and how different theories have evolved, from immunosurveillance to the recent immunoediting theory. We will see how the tumor microenvironment is extremely rich in different immune cell populations. Then we will broadly revise, the main components of the immune system and how it roughly works (immunology in a very small nutshell) to be able to understand how cancer cells not only escape the immune system to become undetectable but also how they can hijack immune cells to help cancer progression. We will also see how cancer cells exploit the mechanisms of self-tolerance to their own benefit. Many times turning immune cells against each other - almost provoking an immune civil war, that in the end generates a highly immune supressive ecosystem that allows tumor cells to thrive in an uncontrolled manner The molecules and cells that are major players in these processes will be addressed. We then conclude this chapter by describing the several new revolutionary approaches to fight cancer using the patient’s own immune system.