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Wülfrath, Germany

Bunger S.,University of Lubeck | Klempt-Giessing K.,University of Lubeck | Toner V.,Randox Laboratories GmbH | Kelly M.,Randox Laboratories GmbH | And 4 more authors.
Biopreservation and Biobanking | Year: 2013

Introduction: Biomarker discovery studies seldom report on pre-analytical effects. We used a novel multiplex protein biochip for colorectal cancer screening to investigate effects of different storage temperatures and repeated freeze-thaw cycles. Methods: This biochip, composed of CEA, IL-8, VEGF, M-CSF, S100A11, C3adesArg, CD26, and CRP, was applied to twenty highly standardized preserved serum samples. Results: Aliquot comparison of long-term storage at-80 C (n=20) versus-170 C (n=20) did not show significant differences for any of the eight markers. In contrast, three freeze-thaw cycles (3×20 aliquots) detected changes in the serum level for all markers (p<0.05) but S100A11 and CD26: levels of CEA, IL-8, C3adesArg, and CRP increased, while VEGF and M-CSF levels decreased. However, applying diagnostic thresholds for CEA, IL-8, and CRP revealed that freeze-thaw cycles did not affect diagnostic performance. In contrast, analysis of samples stored at-80 C compared to-170 C failed to detect one out of three detectable malignancies. Conclusion: We conclude that three freeze-thaw cycles modulated serum marker levels significantly, but do not compromise biochip diagnostic performance. For our marker panel, serum preservation at-80 C seems comparable to-170 C; however, storage at-80 C could lead to misdiagnosis. Our findings emphasize the need for standardized sample collection, processing, storage, and reporting. © 2013, Mary Ann Liebert, Inc. Source


Bunger S.,University of Lubeck | Haug U.,German Cancer Research Center | Kelly F.M.,Randox Laboratories GmbH | Klempt-Giessing K.,University of Lubeck | And 9 more authors.
Journal of Biomolecular Screening | Year: 2011

Development and progression of colon cancer may be related to cytokines. Cytokines with diagnostic value have been identified individually but have not been implemented into clinical praxis. Using a multiplex protein array, the authors explore a panel of cytokines simultaneously and compared its performance to carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9). Serum concentrations of 12 cytokines were simultaneously determined by multiplex biochip technology in 50 colon cancer patients and 50 healthy controls. Serum levels of interleukin-8 (IL-8) and CEA were significantly higher in cancer patients than in healthy controls. Areas under the receiver operating characteristic curves (AUCs) were largest for IL-8, followed by CEA, vascular endothelial growth factor (VEGF), and CA 19-9. Analyses regarding marker combinations showed an advantage over single marker performance for CEA, VEGF, and CA 19-9 but not for IL-8. Multiplex biochip array technology represents a practical tool in cytokine and cancer research when simultaneous determination of different biomarkers is of interest. The results suggest that the assessment of IL-8, CEA, VEGF, and possibly CA 19-9 serum levels could be useful for colon cancer screening with the potential of also detecting early stage tumors. Further validation studies using these and additional markers on a multiplex array format are encouraged. © 2011 Society for Laboratory Automation and Screening. Source


Bunger S.,University of Lubeck | Haug U.,German Cancer Research Center | Kelly M.,Randox Laboratories GmbH | Posorski N.,Jena University Hospital | And 14 more authors.
BMC Cancer | Year: 2012

Background: More than 1.2 million new cases of colorectal cancer are reported each year worldwide. Despite actual screening programs, about 50% of the patients are diagnosed at advanced tumor stages presenting poor prognosis. Innovative screening tools could aid the detection at early stages and allow curative treatment interventions.Methods: A nine target multiplex serum protein biochip was generated and evaluated using a training- and validation-set of 317 highly standardized, liquid nitrogen preserved serum samples comprising controls, adenomas, and colon cancers.Results: Serum levels of CEA, IL-8, VEGF, S100A11, MCSF, C3adesArg, CD26, and CRP showed significant differences between cases and controls. The largest areas under the receiver operating characteristics curve were observed for CEA, IL-8, and CRP. At threshold levels yielding 90% specificity, sensitivities for CEA, IL-8 and CRP were 26%, 22%, and 17%, respectively. The most promising marker combinations were CEA + IL-8 reaching 37% sensitivity at 83% specificity and CEA + CRP with 35% sensitivity at 81% specificity. In an independent validation set CEA + IL-8 reached 47% sensitivity at 86% specificity while CEA + CRP obtained 39% sensitivity at 86% specificity. Early carcinomas were detected with 33% sensitivity for CEA + IL-8 and 28% for CEA + CRP.Conclusions: Apart from CEA, IL-8, and CRP, the screening value of additional blood markers and the potential advantage of combining serum biochip testing with fecal occult blood testing needs to be studied. Multiplex biochip array technology utilizing serum samples offers an innovative approach to colorectal cancer screening. © 2012 Bünger et al.; licensee BioMed Central Ltd. Source

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