Tumor Cell Plasticity in Cancer: Signaling Pathways and Pharmaceutical Interventions

Cellular plasticity, the ability of cells to dynamically alter their phenotypes, is a key driver of tumor evolution. This process is a hallmark of cancer which enables the acquisition of malignant traits, leading to metastasis, progression, and therapy resistance. It is governed by cell-intrinsic factors, such as genomic instability and epigenetic reprogramming, and extrinsic stimuli from the tumor microenvironment. However, a unified framework is still needed to position plasticity as the central process that links these drivers to diverse cancer hallmarks. In this review, we first explore how plasticity enables key steps of tumor evolution, including tumorigenesis, metastasis driven by epithelial-mesenchymal plasticity (EMP), therapy resistance, and cancer stem cell (CSC) dynamics. We then summarize the intrinsic and extrinsic mechanisms that govern this adaptability. Finally, we discuss clinical advances in monitoring and targeting plasticity and highlight how new spatiotemporal technologies can address current research challenges. This review provides a framework positioning cellular plasticity as a central mechanism in cancer evolution, connecting its fundamental drivers to clinical translation. By synthesizing the latest advances, we offer perspectives for developing therapies that integrate prediction, monitoring, and targeting of plasticity to proactively guide cancer evolution toward manageable outcomes.