4. Conclusions
A rapid, sensitive, and specific single-tube dual RT-PCR approach was developed for accurate quantification of NB plasma and tumor tissue M/N ratio. The M/N ratio in NB plasma and tumor tissue detected by single-tube dual RT-PCR approach were consistent with each other. Meanwhile, the M/N ratio in NB tumor tissue detected by single-tube dual RT-PCR approach were consistent with FISH results. By dynamically monitoring 9 MNA NB after surgery, we found the M/N ratio greater than cut-off value before 1-2 months, illustrating that the plasmaMYCN amplification status can be used as a non-invasive indicator of NB recurrence. In summary, plasma circulating cell-free MYCNgene is a non-invasive and prominent indicator for monitoring the recurrence of NB.