An integrated proteomic approach to identifying circulating biomarkers in high-risk neuroblastoma and their potential in relapse monitoring

Abstract

Purpose: Despite intensive treatment regimens, overall survival for high-risk neuroblastoma (HRNB) is still poor. This is in part due to an inability to cure the disease once a patient has reached clinical relapse. Identifying plasma biomarkers of active disease may provide a way of relapse monitoring in HRNB.

Experimental design: In this study, we developed an integrated proteomic approach to identify plasma biomarkers for HRNB.

Results: We identified seven candidate biomarkers (SAA, APOA1, IL-6, EGF, MDC, sCD40L and Eotaxin) for HRNB. These biomarkers were then used to create a multivariate classifier of HRNB, which showed a specificity of 90% (95% confidence interval (CI), 73%, 98%), and a sensitivity of 81% (95%CI, 54%, 96%) for classifying HRNB in a training set. When evaluated on independent test samples, the classifier exhibited 86% accuracy (95% CI, 42%, 100%) of identifying diagnostic samples, and 86% accuracy (95% CI, 70%, 100%) of detecting post-diagnosis longitudinal samples that having active disease.

Conclusion and clinical relevance: Further validation of these biomarkers may improve patients' outcomes by developing a simple blood test for the detection of relapse prior to the development of clinically evident disease. Understanding the role of these biomarkers in immune surveillance of neuroblastoma may also provide a new direction of therapeutic strategies.

Figure 1

Box plots showing the plasma concentrations (mg/ml) of A. SAA and B. APOA1 in High (HRNB), Low (LRNB) and Normal (HC) groups. The box represents values between the 25th and 75th percentile with the horizontal line indicating the median value. ° indicates outlier values.

Figure 2

Receiver Operating Characteristic (ROC) analysis of the seven proteins used in the HRNB classifier for the training set samples. A higher Area Under the ROC Curve (AUC) value indicates increased accuracy for a given marker to predict the presence of HRNB. The p-value of the each of the classification is also indicated. For the biomarkers (Eotaxin, MDC, SCD40L and EGF) that were lower in the high-risk neuroblastoma group, the concentration values multiplied by −1 were used to generate the ROC plots.