RGCC Q&A

Sensitivity: 87% (13% false negatives)

Specificity: 83% (17% false positives)

Cancers in compartmentalized tissues (e.g., brain, testis) may not release CTCs.

Limit of Detection (LoD): \~1.6 CTCs per 1 million blood cells

CTCs remain viable for at least 96 hours post-blood draw under proper conditions.

There’s no fixed value. CTC survival depends on:

* Tumor type and immune status

* Cluster formation and stem-like traits

* Dynamic equilibrium of shedding from tumors

Sensitivity (87%): 87 out of 100 cancer patients will test positive.

Specificity (83%): 83 out of 100 healthy patients will test negative.

Each cancer requires custom media and growth factors to culture CTCs properly.

Onconomics shows drug effect on CTCs. However, clinical response also depends on:

Drug metabolism by the body (pharmacogenetics)

Use ChemoSNIP for metabolism assessment.

Yes. Incorrect cancer-type matching leads to inappropriate CTC culture conditions, impacting results.

Isolation: Immunomagnetic sorting and flow cytometry

Identification: Negative markers (CD45, CD31), Positive markers (EpCAM, Cytokeratin)

EDTA: Preserves cell viability

Antibiotics (Penicillin/Streptomycin): Prevents bacterial growth

QC includes:

• Visual check of vial/sample
• Clot detection
• Flow cytometry pattern
• Microbial contamination screening

Possible causes:

• Compartmentalized tumors (e.g., brain)
• Low shedding or masked by endothelial cells
• Recent systemic therapy (must stop 14 days before sampling)
• Hybrid cells not isolatable with standard methods
• Technical false negatives (13% rate)

Yes. Each run uses:

• Positive/negative controls
• Triplicates
• Reagent tracking
• Accredited validations

No fixed duration. Stem-like CTCs can proliferate rapidly; millions of cells possible within days.

Approximately 1.6 CTCs per 1,000,000 blood cells.

These rates are intrinsic to any diagnostic test, regardless of selection method. High specificity often compromises sensitivity, and vice versa.

1. Sample logged in pre-chamber
2. Distributed to respective labs:

•    Flow cytometry
•    Genetic analysis
•    Cell culture

3. Physician is notified for confirmation

Clinical decision rests with the physician. ChemoSNIP helps evaluate metabolic suitability. Use both tests for a full picture.

If ChemoSNIP shows poor metabolism or the patient cannot tolerate it, **alternative drugs** with both efficacy and metabolic compatibility should be considered.