Background: In neuroblastoma (NB), a genomic profile characterized by segmental chromosome alterations is associated with poorer outcome. The SIOPEN LINES trial (Low and Intermediate Neuroblastoma European Study) was designed to maintain or improve the excellent outcome in low risk patients (LR), whilst diminishing overall treatment burden whenever possible. Treatment is stratified according to the genomic profile in addition to clinical parameters. In intermediate risk (IR) patients, the genomic profile is studied prospectively.
Methods: NB samples with >60% tumor cells are analyzed using pangenomic techniques, with central review, entering of data in the SIOPEN-R-NET database, and return of the clinically relevant conclusions to the treating clinician within six weeks after diagnosis. NB without MYCN amplification are classified into two groups: numerical chromosome alterations (NCA) only, versus segmental chromosome alterations (SCA) >2Mb known to occur recurrently in NB, without or with numerical alterations.
Results: For 277 enrolled patients (190 LR, 87 IR), genomic profiling was performed in 230 cases using MLPA (n=7), aCGH (n=151), SNP-arrays (n=61) or other techniques (n=11). A genomic profile could be determined in 203 cases (131 NCA, 72 SCA). In 27 cases, no result was obtained, either because no copy number changes were seen (n=7), or because of alterations for which the prognostic relevance has not been clearly established (n=10), including small interstitial deletions of chromosomes 8p or 3p, deletions of 5q, 11p, 17p, 19q and 22q, 2 cases with focal amplification of 12q14 encompassing CDK4/MDM2, amplification of 1p34.2, or a gain of 18p. For 10 other cases, no genomic profile could be obtained either due to insufficient material or technical issues. For 47 cases (23 LR, 24 IR), no up-front genomic profiling was performed.
Conclusion: In SIOPEN’s LINES trial, genomic profiling in a diagnostic, real-time setting is feasible, with a success rate of 87% in analyzed cases.