SJPedPanel, a novel pan-cancer gene panel, has shown promising results in enhancing the detection of driver alterations in childhood malignancies. The study, published in Clinical Cancer Research, highlights the panel's ability to accurately identify a wide range of genomic variants critical for understanding and treating pediatric cancers.
The SJPedPanel was validated by resequencing 113 clinical cases encompassing a diverse range of childhood cancer subtypes, including hematologic malignancies, solid tumors, and brain tumors. The panel targets 361 variants previously identified through comprehensive genomic sequencing (WGS, WES, RNAseq).
High Detection Rate of Driver Alterations
The results demonstrated that SJPedPanel detected 91% of the 389 reported driver alterations across the tested samples. This included a 100% detection rate for SNVs, indels, and ITDs. Fusion/SV detection reached 97%, while CNV/LOH detection was 94.6%. Notably, at least one variant was detected in 96.5% of cases, with a median of three variants per case.
Superior Performance Compared to WES
Comparison with whole-exome sequencing (WES) revealed that SJPedPanel covers 88% of SNV, indel, SV, and ITD variants, while WES covers 78%. This indicates that SJPedPanel achieves superior performance for childhood cancers with a panel size approximately 10% the size of WES.
Challenges in Structural Variant Detection
The study also highlighted challenges in detecting structural variants (SVs). While the panel successfully detected many fusion gene pairs, some SVs with breakpoints in intergenic or non-covered regions were missed. For example, the panel missed RUNX1::RUNX1T1 in one case because RUNX1T1 introns were not included. The researchers noted that balancing panel size with comprehensive coverage of intronic regions involved in oncogenic fusions remains a challenge.
Successful Detection of ITDs
SJPedPanel demonstrated exclusive coverage of the UBTF gene, successfully detecting UBTF tandem duplications in two pediatric AML cases. These ITDs are often mistakenly detected as small indels in literature, highlighting the panel's enhanced detection capabilities.
Clinical Implications
The SJPedPanel represents a significant advancement in the genomic profiling of childhood cancers. Its ability to accurately and efficiently detect driver alterations can inform diagnosis, prognosis, and treatment decisions, ultimately improving outcomes for pediatric cancer patients. Further refinement of the panel, particularly in the detection of structural variants, will further enhance its clinical utility.
