Clonal Evolution
The process by which cancer cells accumulate genetic mutations over time, leading to tumor heterogeneity and potential treatment resistance.
Full Definition
Clonal evolution describes the dynamic genetic changes that occur within cancer cell populations during disease progression and treatment. As tumors grow and respond to selective pressures such as chemotherapy or radiation, different subclones with varying genetic profiles emerge and compete for survival. This evolutionary process contributes to intratumoral heterogeneity and is a major mechanism underlying acquired drug resistance. The concept is fundamental to understanding why cancers may initially respond to treatment but later become refractory, and it informs strategies for sequential therapy selection and combination treatment approaches.
In Context
- "Serial biopsies revealed clonal evolution with acquisition of EGFR T790M mutation after initial tyrosine kinase inhibitor therapy." — Research paper
- "The tumor's clonal evolution pattern suggested early divergence from the primary site, indicating aggressive metastatic potential." — Molecular pathology report