3.4. Dynamic detection of M/N ratio in NB plasma
The postoperative recurrence of NB patients is one of the key reasons
for the high mortality of NB. Therefore, there is urgent need to develop
early and dynamic monitoring methods for recurrence of NB. The clinical
significance of MYCN in monitoring recurrence in NB patients was
evaluated by dynamically monitoring the plasma M/N ratios of 9 patients
with MNA cases after surgery. As shown in Fig 4, the plasma M/N ratio of
9 MNA NB patients dropped below 2.0 after surgical treatment, which is
consistent with the M/N ratio of non-MNA amplified tumor patients. In
addition, we found the M/N ratio of P2 and P9 was greater than 2.0
before 1-2 months recurrence. Therefore, NB plasma circulating cell-freeMYCN can be used as an early, non-invasive and dynamic monitoring
indicator for relapse in NB patients.