DNA in residual tumor cells

“DNA in residual tumor cells” refers to the **tumor-derived genetic material**—specifically fragments of **circulating tumor DNA (ctDNA)**—that remain detectable after local or systemic cancer treatment. This concept is central to the detection of **molecular/minimal residual disease (MRD)**, which is defined as the presence of microscopic numbers of malignant cells or their nucleic acids that persist following therapy and are not visible on imaging. Detection typically relies on highly sensitive molecular techniques such as next-generation sequencing or PCR-based assays targeting known somatic mutations or epigenetic changes present in the original tumor. The presence of ctDNA post-treatment is strongly associated with an increased risk for cancer recurrence and can serve as a noninvasive biomarker for monitoring patient prognosis and guiding further therapeutic decisions. However, “DNA in residual tumor cells” itself is not a discrete molecular target like a receptor or enzyme; rather, it represents a class of biomarkers used for clinical surveillance. There are no drugs that directly interact with this “target,” nor does it have canonical abbreviations beyond those describing its context (“ctDNA,” “MRD”). The term may be considered imprecise because it describes material used for detection/monitoring rather than an actionable therapeutic target.[1][2][3]

Other names

Circulating tumor DNA in residual tumor cellsctDNA in residual tumor cellsMolecular residual disease (MRD) DNATumor-derived cell-free DNA (cfDNA)