Serially Quantifying TERT Rearrangement Breakpoints in ctDNA Enables Minimal Residual Disease Monitoring in Patients...

Area of Science:

• Oncology
• Molecular Diagnostics
• Genetics

Background:

• High-risk neuroblastoma often involves TERT gene rearrangements, leading to poor prognosis when combined with RAS/MAPK/ALK pathway mutations.
• Current molecular diagnostic tools for this vulnerable pediatric subgroup are limited, creating an unmet clinical need for real-time monitoring.

Purpose of the Study:

• To develop and validate a liquid biopsy-based monitoring strategy for pediatric patients with TERT-rearranged high-risk neuroblastoma.
• To assess the utility of droplet digital PCR assays for quantifying TERT rearrangement breakpoints and ALK mutations in liquid biopsies.

Main Methods:

• Longitudinal collection of liquid biopsies (peripheral blood and bone marrow plasma) and tumor samples from 55 patients.
• Development of droplet digital PCR assays to quantify patient-individualized TERT rearrangement breakpoint copies, ALK copy numbers, and ALK p.R1275Q mutation frequencies.
• Comparison of liquid biopsy marker detection with current gold-standard diagnostics.

Main Results:

• Detection and quantification of unique TERT rearrangement breakpoints in cell-free DNA from peripheral blood plasma enabled improved therapy response assessment and early relapse detection.
• Proof-of-concept for minimal residual disease detection in bone marrow plasma using TERT rearrangement breakpoints.
• TERT rearrangement breakpoints, alone or combined with RAS/MAPK/ALK mutations, demonstrated robust and sensitive biomarker potential for disease activity.

Conclusions:

• Liquid biopsy assays targeting TERT rearrangement breakpoints offer a sensitive and specific method for monitoring TERT-driven neuroblastoma in pediatric patients.
• This approach provides superior spatial and temporal resolution of disease activity compared to current diagnostics, aiding in clinical routine.
• The developed digital PCR strategy addresses the unmet need for real-time molecular monitoring in high-risk neuroblastoma.