Quantitative analysis of minimal residual disease predicts relapse in children with B-lineage acute lymphoblastic...

Area of Science:

• Pediatric Oncology
• Molecular Diagnostics

Background:

• Minimal residual disease (MRD) is a key prognostic factor in B-lineage acute lymphoblastic leukemia (ALL).
• Accurate MRD detection is crucial for risk stratification and treatment individualization.

Purpose of the Study:

• To evaluate the clinical utility of real-time quantitative polymerase chain reaction (PCR) for MRD detection in childhood B-lineage ALL.
• To identify children at high risk of relapse based on MRD levels.
• To assess the impact of MRD levels on long-term relapse risk.

Main Methods:

• Prospective trial involving 284 children with B-lineage ALL.
• Real-time quantitative PCR analysis of antigen receptor gene rearrangements for MRD detection.
• Recursive partitioning and clinical characteristics analysis to determine optimal MRD cutoff levels.

Main Results:

• A significant difference in 5-year relapse risk was observed between children with and without detectable MRD (5% vs. 44%, P < .001).
• An optimal MRD cutoff of 10^-3 was identified, with high MRD levels (≥10^-3) associated with a 72% relapse risk and a 10.5-fold increased risk.
• A linear association between MRD level and subsequent relapse risk was established.

Conclusions:

• Real-time quantitative PCR for MRD detection is a valuable tool for identifying high-risk children with B-lineage ALL.
• Treatment regimens have been altered to intensify therapy for children with MRD levels ≥10^-3 post-induction chemotherapy.
• This approach aims to decrease the subsequent relapse risk in pediatric ALL patients.