To evaluate plasma cell-free
DNA (
cfDNA) as a promising
biomarker for
neuroblastoma (NB)
tumor burden. Seventy-nine eligible patients with newly diagnosed NB were recruited from Beijing Children's Hospital between April 2016 and April 2017. Additionally, from September 2011 to June 2017, 79 patients with stable NB were evaluated with a median follow-up time of 21 months. Approximately 2 mL of peripheral blood was drawn upon enrollment, and plasma
cfDNA levels were measured via quantitative polymerase chain reaction (qPCR). Total
cfDNA analysis was performed using the long interspersed nuclear
element 1 (LINE-1) 79 bp fragment, and
DNA integrity was calculated by the ratio of the LINE-1 300 bp fragment to the LINE-1 79 bp fragment. A total of 79 NB patients with a median age of 36 months comprised the group of newly diagnosed NB patients. The main primary
tumor site was the retroperitoneal and adrenal region (81%). Three or more metastatic sites were found in 17.7% of patients. Stable NB patients older than 18 months comprised 98.7% of the stable NB patients.
Neuron-specific enolase (NSE),
lactate dehydrogenase (LDH), and
cfDNA levels were dramatically increased in the newly diagnosed NB patients and significantly different from those in the stable NB patients. Moreover, the concentration of
cfDNA was much higher in patients with larger
tumors. By analyzing the area under the receiver operator characteristic (ROC) curve (AUC), the areas of total
cfDNA, NSE, and LDH levels were 0.953, 0.929, and 0.906, respectively. The sensitivity and specificity data clarified that the level of circulating
cfDNA in plasma can be considered as a reliable
biomarker for describing
tumor load in NB. The plasma
cfDNA concentration was as good as the levels of LDH and NSE to discriminate the
tumor burden in children with NB.