Precision medicine in pediatric oncology: Lessons learned and next steps

Sepsis: Personalized Medicine Utilizing 'Omic' Technologies-A Paradigm Shift?

Sepsis has over the years proven a considerable challenge to physicians and researchers. Numerous pharmacological and non-pharmacological interventions have been tested in trials, but have unfortunately failed to improve the general prognosis. This has led to the speculation that the sepsis population may be too heterogeneous to be targeted with the traditional one treatment suits all’ approach. Recent advances in genetic and biochemical analyses now allow genotyping and biochemical characterisation of large groups of patients via the ‘omics’ technologies. These new opportunities could lead to a paradigm shift in the approach to sepsis towards personalised treatments with interventions targeted towards specific pathophysiological mechanisms activated in the patient. In this article, we review the potentials and pitfalls of using new advanced technologies to deepen our understanding of the clinical syndrome of sepsis.

Precision medicine in pediatric oncology

Outcome in treatment of childhood cancers has improved dramatically since the 1970s. This success was largely achieved by the implementation of cooperative clinical research trial groups that standardized and developed treatment of childhood cancer. Nevertheless, outcome in certain types of malignancies is still unfavorable. Intensification of conventional chemotherapy and radiotherapy improved outcome only marginally at the cost of acute and long-term side effects. Hence, it is necessary to develop targeted therapy strategies.Here, we review the developments and perspectives in precision medicine in pediatric oncology with a special focus on targeted drug therapies like kinase inhibitors and inducers of apoptosis, the impact of cancer genome sequencing and immunotherapy.

Targeted Sequencing of Malignant Supratentorial Pediatric Brain Tumors Demonstrates a High Frequency of Clinically Relevant Mutations

Pediatric brain tumors cause more deaths than any other childhood malignancy, and the identification of potentially actionable genomic alterations in this rare heterogeneous group of tumors may improve treatment and outcome. The genetic landscape of common posterior fossa tumors has been described in the past several years, yet the classification of malignant pediatric supratentorial tumors remains controversial. Next-generation sequencing (NGS) is a promising tool to evaluate multiple genes concurrently. The clinical utility of NGS has not been proven in pediatric brain tumors. We identified patients diagnosed with high-grade supratentorial pediatric brain tumors resected between 2008 and 2012 at our institution. DNA from 12 formalin-fixed paraffin-embedded tumor samples from 9 patients was analyzed, including 3 paired samples from diagnosis and relapse. A panel of 194 cancer-related genes was sequenced using targeted next-generation deep sequencing. Genetic findings were correlated with histology, immunohistochemistry, treatment, and survival. We found one or more pathologic genetic change (mutation, amplification, or deletion) in 8 of 9 (89%) of patients studied. Epidermal Growth Factor Receptor ( EGFR) mutations were found in 3 patients, 2 of which had an exon 20 insertion not previously described in pediatric malignancy. Additional genetic changes were found in EGFR and Platelet-Derived Growth Factor Receptor Alpha ( PDGFRA) at relapse not present in the initial samples. Familial cancer predisposition syndromes were suggested by mutations found in 3 genes in 4 patients, including TP53, MSH2, and CHEK2. Seven of 9 patients in this study died of their disease. In summary, targeted deep sequencing may be used in rare pediatric brain tumors to identify driver mutations for targeted therapy, suggest constitutional and familial testing for cancer predisposition syndromes, and select molecular targets worthy of further study.

Comparative RNA-Sequencing Analysis Benefits a Pediatric Patient With Relapsed Cancer

Clinical detection of sequence and structural variants in known cancer genes points to viable treatment options for a minority of children with cancer.¹ To increase the number of children who benefit from genomic profiling, gene expression information must be considered alongside mutations.^2,3 Although high expression has been used to nominate drug targets for pediatric cancers,^4,5 its utility has not been evaluated in a systematic way.⁶ We describe a child with a rare sarcoma that was profiled with whole-genome and RNA sequencing (RNA-Seq) techniques. Although the tumor did not harbor DNA mutations targetable by available therapies, incorporation of gene expression information derived from RNA-Seq analysis led to a therapy that produced a significant clinical response. We use this case to describe a framework for inclusion of gene expression into the clinical genomic evaluation of pediatric tumors.

Precision medicine in pediatric oncology

PURPOSE OF REVIEW

The current review describes recent advances and unique challenges in precision medicine for pediatric cancers and highlights clinical trials assessing the clinical impact of targeted therapy matched to molecular alterations identified by tumor profiling.

RECENT FINDINGS

Multiple prospective clinical sequencing studies in pediatric oncology have been reported in the last 2 years. These studies demonstrated feasibility of sequencing in the clinic and revealed a rate of actionable variants that justifies the development of precision trials for childhood cancer. A number of precision medicine trials are recently completed, underway or in development and these will be reviewed herein, with a focus on highlighting aspects of precision medicine trial design relevant to pediatric oncology.

SUMMARY

The primary results of the first round of pediatric precision oncology clinical trials will provide us with a greater understanding of the clinical impact of linking tumor profiling to selection of targeted therapies. The aggregation of sequencing and clinical data from these trials and the results of biologic investigations linked to these trials will drive further discoveries and broaden opportunities for precision medicine for children with cancer.

Cell death-based treatment of childhood cancer

Any therapy that aims at eradicating a cancerous growth will have at its core a cell death-inducing component. Here we argue that paediatric oncology presents with its unique set of considerations and problems, which—while taking the lead from oncological research experiences obtained from the adult population—need to be clinically evaluated independently. This is particularly true when considering long-term side effects. Precision medicine offers a promising new approach in therapy, but given as a monotherapy and in a limited combination, as found in an apoptosis inducer/sensitiser combination, it will most likely lead to mutation escape of the target cell population and the emergence of resistance. However, using the increasing amount of the molecular data as the basis for a complex combination therapy combining several key components such as cell death-inducing agents, kinase inhibitors and BH3 mimetics, holds great promise.

Precision Medicine in Pediatric Neurooncology: A Review

Central nervous system tumors are the leading cause of cancer related death in children. Despite much progress in the field of pediatric neurooncology, modern combination treatment regimens often result in significant late effects, such as neurocognitive deficits, endocrine dysfunction, secondary malignancies, and a host of other chronic health problems. Precision medicine strategies applied to pediatric neurooncology target specific characteristics of individual patients' tumors to achieve maximal killing of neoplastic cells while minimizing unwanted adverse effects. Here, we review emerging trends and the current literature that have guided the development of new molecularly based classification schemas, promising diagnostic techniques, targeted therapies, and delivery platforms for the treatment of pediatric central nervous system tumors.

Clinical Impact of Genomic Information in Pediatric Leukemia

Pediatric leukemia remains a significant contributor to childhood lethality rates. However, recent development of new technologies including next-generation sequencing (NGS) has increased our understanding of the biological and genetic underpinnings of leukemia, resulting in novel diagnostic and treatment paradigms. The most prevalent pediatric leukemias include B-cell acute lymphoblastic leukemia (B-ALL) and acute myeloid leukemia (AML). These leukemias are highly heterogeneous, both clinically and genetically. There are multiple genetic subgroups defined by the World Health Organization, each with distinct clinical management. Clinical laboratories have started adopting genomic testing strategies to include high-throughput sequencing assays which, together with conventional cytogenetic techniques, enable optimal patient care. This review summarizes genetic and genomic techniques used in clinical laboratories to support management of pediatric leukemia, highlighting technical, biological, and clinical advances. We illustrate clinical utilities of comprehensive genomic evaluation of leukemia genomes through clinical case examples, which includes the interrogations of hundreds of genes and multiple mutation mechanisms using NGS technologies. Finally, we provide a future perspective on clinical genomics and precision medicine.

The impact of hereditary cancer gene panels on clinical care and lessons learned

Mutations in hereditary cancer syndromes account for a modest fraction of all cancers; however, identifying patients with these germline mutations offers tremendous health benefits to both patients and their family members. There are about 60 genes that confer a high lifetime risk of specific cancers, and this information can be used to tailor prevention, surveillance, and treatment. With advances in next-generation sequencing technologies and the elimination of gene patents for evaluating genetic information, we are now able to analyze multiple genes simultaneously, leading to the widespread clinical use of gene panels for germline cancer testing. Over the last 4 years since these panels were introduced, we have learned about the diagnostic yield of testing, the expanded phenotypes of the patients with mutations, and the clinical utility of genetic testing in patients with cancer and/or without cancer but with a family history of cancer. We have also experienced challenges including the large number of variants of unknown significance (VUSs), identification of somatic mutations and need to differentiate these from germline mutations, technical issues with particular genes and mutations, insurance coverage and reimbursement issues, lack of access to data, and lack of clinical management guidelines for newer and, especially, moderate and low-penetrance genes. The lessons learned from cancer genetic testing panels are applicable to other clinical areas as well and highlight the problems to be solved as we advance genomic medicine.

Approaching the third decade of paediatric palliative oncology investigation: historical progress and future directions

Paediatric palliative care (PPC) endeavours to alleviate the suffering and improve the quality of life of children with serious illnesses and their families. In the past two decades since WHO defined PPC and called for its inclusion in paediatric oncology care, rigorous investigation has provided important insights. For example, the first decade of research focused on end-of-life experiences of the child and the family, underscoring the high prevalence of symptom burden, the barriers to parent-provider concordance with regards to prognosis, as well as the need for bereavement supports. The second decade expanded PPC oncology investigation to include the entire cancer continuum and the voices of patients. Other studies identified the need for support of parents, siblings, and racial and ethnic minority groups. Promising interventions designed to improve outcomes were tested in randomised clinical trials. Future research will build on these findings and pose novel questions about how to continue to reduce the burdens of paediatric cancer.