Elevated Cell-Free DNA Measured by a Simple Assay Is Associated With Increased Rate of Colorectal Cancer Relapse.
OBJECTIVE
For patients with early stage colorectal cancer (CRC), markers of high-risk relapse are needed. In a previous study on 38 randomly selected patients with CRC, we found good correlation between presurgery cell-free DNA (CFD) concentrations and standard prognostic factors. In the current study, we revisited the same patients at 5-year survival, aiming to evaluate the predictive power of presurgery CFD levels.


METHODS
We revisited 38 patients with CRC previously analyzed for 5-year outcome. CFD was measured using a simple fluorescent assay that we developed.


RESULTS
All recurrent patients and patients who had died of cancer within 5 years were shown to have presurgery CFD values above 800 ng/mL. The negative predictive value for cancer-related disease was 100%. Cox regression analysis for disease-free survival showed a hazard ratio of 6.03 (P = .003) for CFD, which was higher than the ratio of the disease stage, 1.9 (P = .006). The survival-free curve of stage I and II patients with elevated CFD was significantly different from patients with normal levels (P = .0136); 5 (41.7%) of 12 patients had died of cancer or had experienced a recurrence.


CONCLUSIONS
CFD may possibly be a decisive criterion to identify patients with local disease who might benefit from adjuvant chemotherapy.
From the Department of General Surgery.
David
D
Czeiger
From the Department of General Surgery.
Gad
G
Shaked
From the Department of General Surgery.
Gilbert
G
Sebbag
From the Department of General Surgery.
Alex
A
Vakhrushev
From the Department of General Surgery.
Anatoly
A
Flomboym
Clinical Research Center Department of Clinical Biochemistry and Pharmacology.
Yotam
Y
Lior
Department of Oncology, Soroka University Medical Center and Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Olga
O
Belochitski
Department of Oncology, Soroka University Medical Center and Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Samuel
S
Ariad
Department of Clinical Biochemistry and Pharmacology amosd@bgu.ac.il.
Amos
A
Douvdevani
D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D015179:Colorectal Neoplasms / Q000097:blood* / Q000401:mortality / Q000473:pathology; D004247:DNA / Q000097:blood*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood* / Q000401:mortality; D016016:Proportional Hazards Models; D012680:Sensitivity and Specificity
D014408:Biomarkers, Tumor; D004247:DNA
Biomarkers; Circulating cell-free DNA (CFD); Colorectal cancer (CRC); Hazard ratio; Prognosis; Treatment decisive marker