Cancer continues to be the leading cause of death worldwide. According to the World Health Organization, there were 14M new cases of cancer worldwide in 2012. In 2030 there will be nearly 22M. Although advanced targeted therapies have improved survival outcomes for some cancers, the cure rates for the majority of cancers still remain low.
There are many reasons for the challenges that lie ahead. For instance, in a wide range of tumor types, there exists a typically small subpopulation of cells within the cancer that have been termed tumor-initiating cells or cancer stem cells (CSCs). CSCs have been shown to be more chemotherapy and radiation resistant than non-CSCs.
Furthermore, although cancer cells and CSCs are the driving force of tumor development and progression, these transformed cells cannot do it alone. It is the complex interaction between the cancer and surrounding non-malignant cells of the tumor microenvironment (TME), that helps drive the process of cancer progression. So progression from normal to benign, benign to malignant, malignant to metastatic is driven not just by what's happening inside the cancer cell itself but also by what's happening around it.
The big advantage cancer cells have is their ability to mutate and develop resistance following conventional therapies. Fortunately, non-malignant host cells of the TME do not mutate or develop resistance. Therefore, within the context of ecology and Darwinian evolution, the most efficient way to kill a species (cancer cells and CSCs) is to alter its ecosystem (TME).