Circulating serum oncologic miRNA in pediatric juvenile pilocytic astrocytoma patients predicts mural nodule volume

Juvenile pilocytic astrocytomas represent the largest group of pediatric brain tumors. The ideal management for these tumors is early, total surgical resection. To detect and track treatment response, a screening tool is needed to identify patients for surgical evaluation and assess the quality of treatment. The identification of aberrant miRNA profiles in the sera of juvenile pilocytic astrocytoma patients could provide such a screening tool.

The authors reviewed the serum profiles of 84 oncologically relevant miRNAs in pediatric juvenile pilocytic astrocytoma patients via qPCR screening.

miR-21, miR-15b, miR-23a, and miR-146b were significantly elevated in the sera of JPA patients as compared to non-oncologic controls, oncologic controls, and post-JPA resection samples (p < 0.001, 0.022, 0.034, 0.044). miR-21 had the highest AUC on ROC analysis (AUC > 0.99, sensitivity 75%, specificity 100%). All four miRNAs also correlated well with tumor mural nodule size, though they only poorly correlated with total tumor size, including cystic components (Spearman's R²: miR-21 91.7 vs 6.9%, miR-15b 86.3 vs 23.1%, miR-23a 85.8 vs 23.0%, miR-146b 59.8 vs 11.9%).

In this small pilot study, pediatric juvenile pilocytic astrocytoma patients had significant elevations in serum miR-21, miR-15b, miR-23a, and miR-146b levels that do not appear to be driven by hydrocephalus or local distortion of the intracranial contents. These alterations correlate with solid tumor component volume and reverse with complete tumor resection, suggesting that this serum miRNA profile may delineate biomarkers for screening and tracking juvenile pilocytic astrocytoma patients. Additional studies, with a larger cohort, are needed to verify these results.