genomic instability
A hallmark of cancer characterized by increased frequency of mutations and chromosomal aberrations throughout the genome.
Full Definition
Genomic instability refers to the tendency of cancer cells to acquire mutations, chromosomal rearrangements, and other genetic alterations at a higher rate than normal cells. This fundamental characteristic of malignancy results from defects in DNA repair mechanisms, cell cycle checkpoints, or chromosome segregation processes. Genomic instability manifests in various forms including point mutations, insertions and deletions, copy number alterations, chromosomal translocations, and aneuploidy. In clinical practice, measuring genomic instability through metrics such as tumor mutational burden, homologous recombination deficiency scores, or chromosomal instability indices helps predict treatment response, particularly to DNA-damaging agents and immunotherapies. Different types of genomic instability may indicate specific therapeutic vulnerabilities that can be exploited for targeted treatment approaches.
Usage
Usage note: Broader concept than chromosomal instability, which refers specifically to chromosome-level changes.
In Context
- "High levels of genomic instability predicted response to platinum-based chemotherapy." — Clinical trial analysis
- "The tumor displayed classic features of genomic instability with numerous structural variants." — Pathology report