Difference between free circulating plasma and serum DNA in patients with colorectal liver metastases.
Author(s): Thijssen MA, Swinkels DW, Ruers TJ, de Kok JB
Publication: Anticancer Res, 2002, Vol. 22, Page 421-5
PubMed ID: 12017326 PubMed Review Paper? No
Purpose of Paper
Conclusion of Paper
Studies
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Study Purpose
The purpose of this study was to determine the effects of quantifying cell-free circulating DNA in EDTA plasma versus serum among specimens from patients with liver metastases and previously resected colorectal cancer. Plasma was obtained from K3EDTA tubes while serum was obtained from plain tubes, and both were stored at -80 degrees C until analysis.
Summary of Findings:
Serum DNA levels were generally higher than plasma levels and were significantly different between patients and healthy controls (p<0.001), but EDTA plasma levels were not significantly different between cancer patients and healthy controls. For serum, a cut-off value of 35 ng/mL DNA afforded a sensitivity of 42% and a specificity of 93% with regards to prediction of the presence of liver metastasis. The authors state that measured levels of serum DNA were not significantly different between the real time qPCR method and the spectrofluorometric method (PicoGreen), but they do not show data. It was determined that serum DNA levels above the cut-off value were not a reliable predictor of tumor recurrences, but EDTA plasma DNA levels may be predictive of tumor recurrences.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Normal
- Neoplastic - Carcinoma
Platform:
Analyte Technology Platform DNA Fluorometry DNA Real-time qPCR Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Blood and blood products Plasma
Serum
Real-time qPCR Specific Targeted nucleic acid Albumin
Real-time qPCR Specific Technology platform Fluorometry
Preaquisition Diagnosis/ patient condition Liver metastasis of colorectal cancer
Normal
Tumor recurrences
No tumor recurrences