Which statement about MRD reporting is incorrect?

• A. A positive MRD result indicates presence of circulating tumor DNA
• B. Precise MRD results are reported as ctDNA detected or ctDNA not detected
• C. Whole genome sequencing is used to increase MRD sensitivity
• D. MRD results are not used in clinical decisions

Answer: (D)

MRD status reflects whether tumor-derived DNA remains in the circulation after treatment, guiding ongoing management. A positive MRD test means ctDNA is detectable, signaling persistent disease risk. In reporting, MRD results are typically given as ctDNA detected or ctDNA not detected, sometimes with the assay’s sensitivity or allele fraction. For increasing MRD sensitivity, clinicians rely on targeted deep sequencing or digital PCR methods (often tumor-informed panels), rather than whole genome sequencing, which is not routinely used for MRD due to lower sensitivity and higher cost. Importantly, MRD results are used to make clinical decisions—such as adjusting treatment intensity, selecting adjuvant therapy, or determining relapse risk. Therefore, the statement that MRD results are not used in clinical decisions is incorrect.