Molecular profiling of childhood cancer: Biomarkers and novel therapies

Abstract

Background: Technological advances including high-throughput sequencing have identified numerous tumor-specific genetic changes in pediatric and adolescent cancers that can be exploited as targets for novel therapies.

Scope of review: This review provides a detailed overview of recent advances in the application of target-specific therapies for childhood cancers, either as single agents or in combination with other therapies. The review summarizes preclinical evidence on which clinical trials are based, early phase clinical trial results, and the incorporation of predictive biomarkers into clinical practice, according to cancer type.

Major conclusions: There is growing evidence that molecularly targeted therapies can valuably add to the arsenal available for treating childhood cancers, particularly when used in combination with other therapies. Nonetheless the introduction of molecularly targeted agents into practice remains challenging, due to the use of unselected populations in some clinical trials, inadequate methods to evaluate efficacy, and the need for improved preclinical models to both evaluate dosing and safety of combination therapies.

General significance: The increasing recognition of the heterogeneity of molecular causes of cancer favors the continued development of molecularly targeted agents, and their transfer to pediatric and adolescent populations.

Keywords: ALK, anaplastic lymphoma kinase; ALL, acute lymphoblastic leukemia; AML, acute myeloid leukemia; ARMS, alveolar rhabdomyosarcoma; AT/RT, atypical teratoid/rhabdoid tumor; AURKA, aurora kinase A; AURKB, aurora kinase B; BET, bromodomain and extra terminal; Biomarkers; CAR, chimeric antigen receptor; CML, chronic myeloid leukemia; Childhood cancer; DFMO, difluoromethylornithine; DIPG, diffuse intrinsic pontine glioma; EGFR, epidermal growth factor receptor; ERMS, embryonal rhabdomyosarcoma; HDAC, histone deacetylases; Hsp90, heat shock protein 90; IGF-1R, insulin-like growth factor type 1 receptor; IGF/IGFR, insulin-like growth factor/receptor; Molecular diagnostics; NSCLC, non-small cell lung cancer; ODC1, ornithine decarboxylase 1; PARP, poly(ADP-ribose) polymerase; PDGFRA/B, platelet derived growth factor alpha/beta; PI3K, phosphatidylinositol 3′-kinase; PLK1, polo-like kinase 1; Ph +, Philadelphia chromosome-positive; RMS, rhabdomyosarcoma; SHH, sonic hedgehog; SMO, smoothened; SYK, spleen tyrosine kinase; TOP1/TOP2, DNA topoisomerase 1/2; TRAIL, TNF-related apoptosis-inducing ligand; Targeted therapy; VEGF/VEGFR, vascular endothelial growth factor/receptor; mAb, monoclonal antibody; mAbs, monoclonal antibodies; mTOR, mammalian target of rapamycin.

Fig. 1

Schematic representation of two main pathways aberrantly activated in pediatric tumors and corresponding targeted therapies. Molecular inhibitors and monoclonal antibodies are circled in purple and green, respectively.