Circulating Tumor Cells: Oncotrace Cancer Test (RGCC)

Circulating Tumor Cells (CTCs)

Circulating tumor cells are rare cancer cells that detach from a primary tumor or metastases and enter the bloodstream. They can serve as biomarkers for cancer detection, monitoring, and prognosis, as they provide real-time insights into tumor activity without invasive biopsies. CTCs are associated with metastasis risk and treatment response, with higher counts often indicating disease progression. General research supports CTCs as clinically valid tools across various cancers, though detection methods vary in sensitivity and specificity.

Oncotrace Cancer Test by RGCC

The Oncotrace test, developed by RGCC (Research Genetic Cancer Centre, based in Switzerland with labs in Greece), is a liquid biopsy designed to detect and analyze CTCs in blood samples. It aims to establish a baseline cancer status, monitor treatment progress, identify tumor origins, and assess prognosis. Applicable to all cancer types, it is particularly used for patients with confirmed diagnoses, during treatment, or in remission to detect potential recurrence.How It Works

• Sample Collection: A 10-15 ml blood sample is drawn (or tissue/CSF for brain/CNS cancers). Patients should wait 7-21 days post-chemotherapy to avoid interference.
• Analysis: The sample is shipped to RGCC's lab for flow cytometry-based isolation and enumeration of CTCs. This identifies CTC count (cells/ml), immunophenotype (surface markers to determine tumor origin and type), and stemness markers (indicating cancer cell aggressiveness and activity).
• Turnaround Time: Results are available in 7-10 business days.
• Cost: Approximately €800 (excluding additional fees like blood draws or consultations; USD equivalent varies by exchange rate).
• Storage: Sample components are stored for up to 6 months for potential further use.

What It DetectsThe test provides three core metrics:

• CTC Count: Quantifies cancer cells in the blood, correlating with disease stage (e.g., higher counts suggest advanced progression; limits vary by cancer type, such as <20 cells/ml for prostate cancer).
• Phenotype Markers: Tissue-specific markers (e.g., PSMA for prostate, MUC-1 for breast) to identify tumor origin, predict resistance, and monitor response. Positive markers indicate active subpopulations of cancer cells.
• Stemness Markers: Assess cancer stem cell activity (e.g., CD44, CD133, Sox-2). "On" status signals ongoing proliferation or recurrence risk, even with low CTC counts.

Example markers from a sample report (prostate cancer case):

Category	Marker	Example Result	Interpretation
Hematologic (CD45+)	CD34	Negative	No hematologic stem cells detected
Non-Hematologic (CD45-)	EpCam	Positive (50%)	Epithelial origin, common in solid tumors
Stemness	CD133	Positive (25%)	Indicates tumor stem cell presence
Cancer-Specific	PSMA	Positive (75%)	Prostate cancer antigen

Results are interpreted relative to baselines: e.g., declining CTCs suggest effective treatment, while increases or active stemness markers may warrant changes.Benefits and Uses

• Baseline and Monitoring: Establishes initial cancer metrics and tracks changes to evaluate treatment efficacy (e.g., plateaued CTCs may indicate partial response).
• Prognosis: Provides insights into disease progression and recurrence risk, beyond traditional imaging or markers.
• Personalization: Helps tailor therapies by identifying resistant cell types or unknown primaries.
• Non-Invasive: Blood-based, complementing biopsies or scans. Users report it as useful for post-treatment surveillance, with some testimonials highlighting its role in guiding integrative care.

Scientific Evidence and ValidationRGCC reports 86-87% sensitivity and 83-84% specificity for CTC detection in cancers like breast, based on clinical samples. Independent studies on CTCs (not specific to Oncotrace) confirm their utility as biomarkers. RGCC-cited research includes:

• Flow cytometry for breast cancer CTC detection (2019 study by RGCC authors).
• Machine learning-based colorectal screening using CTCs (2021, Entropy journal). Broader reviews emphasize CTCs' role in prognosis and monitoring. One source claims 92% true positive and 95% true negative rates for RGCC tests overall.

Limitations and Controversies

• Not Universally Approved: Lacks US CLIA or CAP certification, limiting its use in standard US clinical settings. It's often accessed via functional or integrative medicine providers.
• Detection Gaps: Misses encapsulated, dormant, or brain tumors not shedding CTCs; not 100% accurate and should complement other diagnostics.
• User Experiences: In forums, patients report persistent positive results post-surgery, raising concerns about interpretation and follow-up, though some find it promising for early detection.
• Controversy: Described as controversial in some sources due to reliance on proprietary methods and limited independent validation beyond RGCC's studies. Critics note it may overpromise personalized recommendations, while proponents emphasize its sensitivity.

Overall, the Oncotrace test offers a specialized tool for CTC-based cancer monitoring, supported by emerging evidence on liquid biopsies, but it's not a standalone diagnostic and may not align with conventional guidelines in all regions. Consult a healthcare provider for personalized advice.