Molecular assessment of minimal residual disease in PBSC harvests provides prognostic information in neuroblastoma

As almost all patients with high-risk neuroblastomas have autograft, we aimed to determine if minimal residual disease (MRD) quantified by RT-PCR for tyrosine hydroxylase in PBSC is prognostic in neuroblastomas. PBSC harvests from 38 children were analyzed. Seven had harvests positive for TH-mRNA. Patients with a positive MRD had a lower 2-year-overall-survival compared to those with negative MRD (P = 0.04) regardless of whether or not PBSC were re-infused. Patients in CR/VGPR group with positive MRD have hazard ratio of death at 7.3 [1.3-40.5]. In conclusion, molecular MRD status in PBSC of good response group may be of interest as a survival prognostic factor in high-risk neuroblastomas.