ctDNA Testing for Cancer Screening

Current Evidence-Based Applications

The American Society of Clinical Oncology recommends ctDNA testing for EGFR mutation detection in non-small cell lung cancer when tissue biopsy is not feasible, inadequate, or missing 2, 1
The European Society for Medical Oncology suggests that ctDNA testing is useful for identifying resistance mechanisms in patients progressing on targeted therapies 2, 1
Approximately 25% of non-small cell lung cancer patients are "non-shedders" with DNA levels below detection limits, making negative results unreliable 2, 1
The National Comprehensive Cancer Network states that ctDNA plays an important role in predicting recurrence risk and evaluating minimal residual disease in colorectal cancer patients after treatment 3
The American College of Gastroenterology recommends that postoperative ctDNA detection predicts disease recurrence in locally advanced rectal cancer, independent of adjuvant chemotherapy use 4, 5

The American Society of Clinical Oncology notes that negative ctDNA results must be interpreted with extreme caution and never exclude the presence of cancer 2, 1
The College of American Pathologists states that ctDNA testing cannot reliably detect amplifications or fusions compared to tissue testing 2
The International Association for the Study of Lung Cancer warns that low variant allelic frequency of sensitizing mutations is associated with high false-negative rates 2
The American College of Medical Genetics recommends that only clinically validated ctDNA methods performed in CLIA-certified laboratories should be used for clinical decision-making 1

The National Comprehensive Cancer Network advises to proceed with tissue biopsy as the primary diagnostic approach, providing histological diagnosis, comprehensive molecular profiling, and definitive characterization 2, 1
The European Society for Medical Oncology suggests considering ctDNA testing only if tissue cannot be safely obtained or is insufficient for analysis, or if the patient refuses or cannot tolerate biopsy 1, 4
The American Society of Clinical Oncology recommends that if ctDNA testing is performed and negative, one should not rule out cancer based on negative ctDNA alone, and pursue tissue diagnosis through alternative approaches 2, 1