Basics of ctDNA
- What does ctDNA stand for?
a) Circulating tumor DNA
b) Cellular tumor DNA
c) Complex tumor DNA
d) Cancerous tissue DNA
Answer: a - ctDNA is a subset of:
a) RNA fragments
b) Cell-free DNA (cfDNA)
c) Genomic DNA
d) Mitochondrial DNA
Answer: b - ctDNA originates from:
a) Healthy cells
b) Immune cells
c) Tumor cells
d) Bone marrow
Answer: c - The primary method of obtaining ctDNA is:
a) Tissue biopsy
b) Liquid biopsy
c) Endoscopy
d) CT scan
Answer: b - ctDNA is mostly found in:
a) Blood plasma
b) Saliva
c) Urine
d) Cerebrospinal fluid
Answer: a
Characteristics and Detection
- Which is a common method to detect ctDNA?
a) Mass spectrometry
b) PCR-based assays
c) X-ray imaging
d) Ultrasound
Answer: b - ctDNA typically represents:
a) Germline mutations
b) Somatic mutations from tumors
c) Epigenetic modifications only
d) RNA sequences
Answer: b - Which technique is highly sensitive for ctDNA analysis?
a) Sanger sequencing
b) Next-generation sequencing (NGS)
c) Western blotting
d) Flow cytometry
Answer: b - ctDNA fragments are generally:
a) Long (>1,000 base pairs)
b) Short (<200 base pairs)
c) Equal in length to chromosomal DNA
d) Entire chromosomes
Answer: b - The half-life of ctDNA in circulation is approximately:
a) 1-2 hours
b) 24 hours
c) 1 week
d) 1 month
Answer: a
Clinical Applications
- ctDNA is most commonly used in:
a) Imaging-based diagnosis
b) Cancer research and management
c) Viral infections
d) Bone disorders
Answer: b - ctDNA can help in detecting:
a) Tumor mutations
b) Protein levels
c) Hormone imbalances
d) Viral RNA
Answer: a - ctDNA analysis is critical for assessing:
a) Tumor burden
b) White blood cell count
c) Heart rate
d) Organ weight
Answer: a - ctDNA levels correlate with:
a) Tumor size and stage
b) Patient’s age
c) Radiation dose
d) Lymphocyte count
Answer: a - One key application of ctDNA is:
a) Glucose monitoring
b) Treatment resistance detection
c) Blood pressure measurement
d) Brain imaging
Answer: b
Advantages of ctDNA
- One major advantage of ctDNA testing is:
a) High cost
b) Non-invasive nature
c) Requirement for large samples
d) Infrequent utility
Answer: b - ctDNA can provide real-time information about:
a) Tumor dynamics
b) Muscle mass
c) Neuronal activity
d) Skin thickness
Answer: a - ctDNA analysis reduces the need for:
a) Pain medication
b) Repeated tissue biopsies
c) Blood transfusions
d) Chemotherapy
Answer: b - ctDNA can be used for monitoring:
a) Treatment response
b) Blood oxygen levels
c) Platelet aggregation
d) Genetic inheritance patterns
Answer: a - ctDNA is considered superior to tissue biopsy in:
a) Sensitivity to minor genetic variations
b) Analyzing tumor microenvironment
c) Detecting protein expression
d) Assessing organelle structure
Answer: a
Challenges in ctDNA Analysis
- A major challenge in ctDNA analysis is:
a) Its high concentration in blood
b) Its low abundance in circulation
c) Its inability to carry genetic information
d) Lack of reliable detection methods
Answer: b - ctDNA is prone to contamination from:
a) White blood cells
b) cfDNA from healthy cells
c) Platelets
d) Hemoglobin
Answer: b - ctDNA testing can sometimes lead to:
a) Overdiagnosis
b) Low specificity for cancer types
c) Underestimation of tumor burden
d) All of the above
Answer: d - Which cancer types pose a challenge for ctDNA detection?
a) Solid tumors with low shedding rates
b) Blood cancers
c) Tumors with rapid metastasis
d) All cancer types equally
Answer: a - False negatives in ctDNA testing may occur due to:
a) Limited tumor shedding into circulation
b) High cfDNA background
c) Poor sample handling
d) All of the above
Answer: d
Specific Techniques
- Which sequencing method is used for broad mutation analysis in ctDNA?
a) Sanger sequencing
b) Whole-genome sequencing
c) qPCR
d) Immunohistochemistry
Answer: b - Digital droplet PCR is particularly effective for:
a) Quantifying low levels of ctDNA
b) Imaging tumor sites
c) Measuring RNA expression
d) Counting white blood cells
Answer: a - Epigenetic modifications in ctDNA include:
a) Methylation changes
b) Protein folding alterations
c) Lipid modifications
d) DNA replication errors
Answer: a - Hotspot mutation panels for ctDNA testing target:
a) Commonly mutated oncogenes
b) Entire genomes
c) Non-coding RNA regions
d) Mitochondrial DNA
Answer: a - Bioinformatics tools in ctDNA analysis help with:
a) Data interpretation and visualization
b) Blood sample collection
c) Physical tumor excision
d) Radiation therapy administration
Answer: a
Emerging Applications
- ctDNA is being explored for early detection of:
a) Diabetes
b) Alzheimer’s disease
c) Cancer
d) Hypertension
Answer: c - ctDNA-based tests for minimal residual disease (MRD) monitor:
a) Recurrence risk after treatment
b) White blood cell counts
c) Normal tissue repair
d) Hormone fluctuations
Answer: a - Liquid biopsy using ctDNA can identify:
a) Metastatic cancer
b) Cardiovascular disease
c) Vitamin deficiencies
d) Bacterial infections
Answer: a - ctDNA testing is particularly helpful in identifying:
a) Targetable mutations for therapy
b) Heart failure risks
c) Liver enzyme levels
d) Lung capacity changes
Answer: a - ctDNA-guided precision oncology improves:
a) Treatment personalization
b) Radiation tolerance
c) Tissue biopsy frequency
d) Organ transplantation rates
Answer: a
Miscellaneous
- ctDNA reflects:
a) Germline alterations only
b) Tumor-specific genetic alterations
c) Dietary influences
d) Immune responses
Answer: b - ctDNA may detect resistance to:
a) Targeted therapies
b) Radiation therapy
c) Vitamin supplements
d) Physical activity programs
Answer: a - A high ctDNA level during treatment often indicates:
a) Treatment failure
b) Tumor shrinkage
c) Improved prognosis
d) Normal aging
Answer: a - ctDNA mutations commonly target:
a) Oncogenes and tumor suppressor genes
b) Ribosomal RNA
c) Mitochondrial DNA exclusively
d) Viral DNA
Answer: a - ctDNA is being developed as a biomarker for:
a) Personalized oncology
b) Cardiovascular health
c) Neurological disorders
d) Genetic ancestry
Answer: a
Future Directions
- ctDNA holds potential for screening:
a) Multiple cancer types simultaneously
b) Only late-stage cancers
c) Nutrient deficiencies
d) Heart diseases exclusively
Answer: a - Advanced ctDNA assays aim to improve:
a) Sensitivity and specificity
b) Bone density analysis
c) Respiratory monitoring
d) Insulin secretion analysis
Answer: a - ctDNA analysis is integrated with:
a) Immunotherapy strategies
b) Renal function tests
c) Cardiovascular imaging
d) Pulmonary function tests
Answer: a - ctDNA is least suitable for:
a) Non-tumor conditions
b) Monitoring cancer recurrence
c) Identifying drug resistance mutations
d) Early cancer detection
Answer: a - Emerging technologies in ctDNA aim to:
a) Detect cancer at preclinical stages
b) Replace tissue histology
c) Eliminate all tumor burden
d) Predict mental health outcomes
Answer: a - ctDNA methylation analysis is being explored for:
a) Cancer type classification
b) Determining heart rate
c) Measuring oxygen uptake
d) Diagnosing viral infections
Answer: a - ctDNA provides insights into:
a) Tumor heterogeneity
b) Bone structure
c) Neuronal communication
d) Protein folding defects
Answer: a - ctDNA is crucial in tracking:
a) Clonal evolution of tumors
b) Hemoglobin levels
c) Cardiac output
d) Muscle fatigue
Answer: a - Multi-cancer early detection (MCED) tests utilize:
a) ctDNA profiles
b) Endoscopic imaging
c) EEG readings
d) PET scans exclusively
Answer: a - ctDNA is a promising tool for:
a) The future of precision oncology
b) Agricultural engineering
c) Urban planning
d) Meteorological studies
Answer: a
This comprehensive set covers foundational and advanced knowledge about ctDNA, suitable for academic and clinical settings.