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. 2012;7(11):e49843.
doi: 10.1371/journal.pone.0049843. Epub 2012 Nov 27.

Multiparametric analysis of cell-free DNA in melanoma patients

Francesca Salvianti  1 , Pamela Pinzani, Paolo Verderio, Chiara Maura Ciniselli, Daniela Massi, Vincenzo De Giorgi, Marta Grazzini, Mario Pazzagli, Claudio Orlando
Affiliations

Multiparametric analysis of cell-free DNA in melanoma patients

Francesca Salvianti et al. PLoS One. 2012.

Abstract

Cell-free DNA in blood (cfDNA) represents a promising biomarker for cancer diagnosis. Total cfDNA concentration showed a scarce discriminatory power between patients and controls. A higher specificity in cancer diagnosis can be achieved by detecting tumor specific alterations in cfDNA, such as DNA integrity, genetic and epigenetic modifications.The aim of the present study was to identify a sequential multi-marker panel in cfDNA able to increase the predictive capability in the diagnosis of cutaneous melanoma in comparison with each single marker alone. To this purpose, we tested total cfDNA concentration, cfDNA integrity, BRAF(V600E) mutation and RASSF1A promoter methylation associated to cfDNA in a series of 76 melanoma patients and 63 healthy controls. The chosen biomarkers were assayed in cfDNA samples by qPCR. Comparison of biomarkers distribution in cases and controls was performed by a logistic regression model in both univariate and multivariate analysis. The predictive capability of each logistic model was investigated by means of the area under the ROC curve (AUC). To aid the reader to interpret the value of the AUC, values between 0.6 and 0.7, between 0.71 and 0.8 and greater than 0.8 were considered as indicating a weak predictive, satisfactory and good predictive capacity, respectively. The AUC value for each biomarker (univariate logistic model) was weak/satisfactory ranging between 0.64 (BRAF(V600E)) to 0.85 (total cfDNA). A good overall predictive capability for the final logistic model was found with an AUC of 0.95. The highest predictive capability was given by total cfDNA (AUC:0.86) followed by integrity index 180/67 (AUC:0.90) and methylated RASSF1A (AUC:0.89).An approach based on the simultaneous determination of three biomarkers (total cfDNA, integrity index 180/67 and methylated RASSF1A) could improve the diagnostic performance in melanoma.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Biomarkers distribution in cases and controls.
Box plots reflecting the distribution in cases and controls of total cfDNA (Panel A), integrity index 180/67 (Panel B), methylated RASSF1A (Panel C), and BRAFV600E (Panel D). Each box indicates the 25th and 75th percentiles. The horizontal line inside the box indicates the median, and the whiskers indicate the extreme measured values.
Figure 2
Figure 2. ROC Curves deriving from the univariate logistic analysis.
ROC curves derived from the univariate logistic analysis corresponding to total cfDNA (AUC = 0.85), integrity index 180/67 (AUC = 0.76), methylated RASSF1A (AUC = 0.69) and BRAFV600E (AUC = 0.64).
Figure 3
Figure 3. ROC Curve deriving from the multivariate final logistic model.
ROC curve derived from the final multivariate logistic model (AUC = 0.95).
Figure 4
Figure 4. Contribution of each biomarker to the final model - ROC Curves.
ROC curves corresponding to the contribution of each biomarker in the final multivariate logistic model. Without total cfDNA (AUC = 0.86), without integrity index 180/67 (AUC = 0.90), without methylated RASSF1A (AUC = 0.89).
Figure 5
Figure 5. Sequential approach.
Diagnostic performance increment (in terms of AUC) achieved by moving from cfDNA alone (AUC = 0.85; 95%CI = 0.79–0.92) to cfDNA and integrity index 180/67 (AUC = 0.89; 95%CI = 0.84–0.95) and to cfDNA, integrity index 180/67 and methylated RASSF1A (AUC = 0.95; 95%CI = 0.91–0.98).
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References

    1. Hodgson DR, Wellings R, Orr MC, McCormack R, Malone M, et al. (2010) Circulating tumour-derived predictive biomarkers in oncology. Drug Discov Today 15: 98–101. - PubMed
    1. Fleischhacker M, Schmidt B (2007) Circulating nucleic acids (CNAs) and cancer-a survey. Biochim Biophys Acta 1775: 181–232. - PubMed
    1. Jung K, Fleischhacker M, Rabien A (2010) Cell-free DNA in the blood as a solid tumor biomarker–a critical appraisal of the literature. Clin Chim Acta 411: 1611–24. - PubMed
    1. Wang BG, Huang HY, Chen YC, Bristow RE, Kassauei K, et al. (2003) Increased plasma DNA integrity in cancer patients. Cancer Res 63: 3966–8. - PubMed
    1. Umetani N, Giuliano AE, Hiramatsu SH, Amersi F, Nakagawa T, et al. (2006) Prediction of breast tumor progression by integrity of free circulating DNA in serum. J Clin Oncol 24: 4270–6. - PubMed

Publication types

Grants and funding

This study was funded by the Istituto Toscano Tumori (ITT; www.ittumori.it). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.