tumor heterogeneity
Variation in cellular characteristics, genetics, and behavior within a single tumor or between tumor sites.
Full Definition
Tumor heterogeneity refers to the diverse cellular populations that exist within a single tumor mass or between different tumor sites in the same patient, resulting from genetic evolution and selective pressures during cancer progression. This heterogeneity can be spatial (different areas of the same tumor) or temporal (changes over time). Intratumoral heterogeneity poses significant challenges for precision medicine approaches, as sampling bias may miss important subclones, and targeted therapy may select for resistant populations. Understanding tumor heterogeneity is crucial for developing effective treatment strategies and interpreting biomarker studies.
Usage
Usage note: Specify whether referring to spatial or temporal heterogeneity when possible.
In Context
- "Tumor heterogeneity may explain the varied response to targeted therapy observed across different metastatic sites." — Research discussion
- "Spatial tumor heterogeneity was evident on genomic analysis of multiple tissue samples from the same lesion." — Molecular pathology report