# Complexity in cancer stem cells and tumor evolution: towards precision medicine

## TL;DR

This review explores the plasticity of cancer stem cells and tumor evolution, emphasizing their impact on metastasis and implications for developing personalized cancer therapies.

## Contribution

It highlights the dynamic phenotypic switching of cancer stem cells and discusses how understanding this plasticity can inform precision medicine strategies.

## Key findings

- Cancer stem cell depletion can lead to phenotypic switching in tumor cells.
- Plasticity influences metastatic potential and tumor heterogeneity.
- Microenvironment and immune system modulate cancer cell phenotypes.

## Abstract

In this review, we discuss recent advances on the plasticity of cancer stem cells and highlight their relevance to understand the metastatic process and to guide therapeutic interventions. Recent results suggest that the strict hierarchical structure of cancer cell populations advocated by the cancer stem cell model must be reconsidered since the depletion of cancer stem cells leads the other tumor cells to switch back into the cancer stem cell phenotype. This plasticity has important implications for metastasis since migrating cells do not need to be cancer stem cells in order to seed a metastasis. We also discuss the important role of the immune system and the microenvironment in modulating phenotypic switching and suggest possible avenues to exploit our understanding of this process to develop an effective strategy for precision medicine.