tumor heterogeneity
The genetic and phenotypic diversity present within a single tumor or between different tumor sites in the same patient.
Full Definition
Tumor heterogeneity refers to the complex genetic, epigenetic, and phenotypic differences that exist both within individual tumors (intratumoral heterogeneity) and between primary and metastatic sites (intertumoral heterogeneity). This diversity arises through ongoing mutagenic processes and clonal evolution during cancer progression. Tumor heterogeneity poses significant challenges for cancer genomics and precision medicine, as a single biopsy may not capture the full mutational landscape of a patient's cancer. Understanding and accounting for heterogeneity is crucial for accurate genomic profiling and effective treatment strategies.
Usage
Usage note: Distinguish between intratumoral and intertumoral heterogeneity when applicable.
In Context
- "Tumor heterogeneity complicated the interpretation of the multi-region sequencing results." — Research methodology paper
- "The presence of significant tumor heterogeneity may explain the mixed response to targeted therapy." — Clinical case report