circulating tumor DNA
Cell-free DNA fragments released by tumors into the bloodstream, used for non-invasive monitoring and genomic profiling.
Full Definition
Circulating tumor DNA (ctDNA) consists of short DNA fragments shed by cancer cells into the bloodstream through processes such as apoptosis, necrosis, and active secretion. ctDNA represents a small fraction of total circulating cell-free DNA but carries tumor-specific genetic and epigenetic alterations. Liquid biopsy analysis of ctDNA enables non-invasive tumor genotyping, monitoring of treatment response, detection of minimal residual disease, and surveillance for disease recurrence. This technology is rapidly evolving and offers advantages over traditional tissue biopsies in terms of accessibility and ability to capture tumor heterogeneity.
Usage
Usage note: Use 'ctDNA' as the preferred abbreviation in clinical documentation.
In Context
- "Circulating tumor DNA analysis detected an EGFR T790M resistance mutation." — Molecular profiling report
- "ctDNA levels decreased significantly following targeted therapy initiation." — Response monitoring