circulating tumor DNA
Pronunciation: SUR-kyu-lay-ting TOO-mor D-N-A
Also written as: ctDNA — circulating tumor DNA
DNA fragments shed by tumors into the bloodstream, used for liquid biopsy and monitoring treatment response in lung cancer patients.
Full Definition
Circulating tumor DNA (ctDNA) represents a revolutionary advancement in thoracic oncology diagnostics and monitoring. These tumor-derived DNA fragments are released into the bloodstream through tumor cell death and can be detected using sensitive molecular techniques. In lung cancer, ctDNA is used for initial molecular profiling when tissue is insufficient, monitoring treatment response, detecting minimal residual disease after surgery, and identifying mechanisms of resistance to targeted therapies. The non-invasive nature of liquid biopsy makes ctDNA particularly valuable for serial monitoring and for patients who cannot undergo tissue biopsy procedures.
Usage
Usage note: Abbreviate as ctDNA after first use; distinguish from total cell-free DNA which includes non-tumor DNA.
In Context
- "Serial circulating tumor DNA monitoring revealed emergence of a T790M resistance mutation during EGFR inhibitor therapy." — Resistance monitoring report
- "Circulating tumor DNA analysis identified an EGFR exon 19 deletion when tissue biopsy was not feasible." — Molecular testing report