Building bridges: precision medicine in pediatric oncology

Childhood cancer is the leading cause of death in children and young adults in developed countries. To improve outcomes and minimize side effects, the field of “precision medicine” is being explored, aiming to select treatments based on unique characteristics of cancer cells. Large-scale studies analyzing DNA and RNA traits of pediatric cancer have shown major differences between cancers in children and adults. Over 50% of tumors have shown alterations that might make them sensitive to specific drugs. However, efficacy of targeted treatments remains challenging to predict. Therefore, novel functional methods including drug sensitivity testing on tumor derived cells (“organoids”) are investigated to complement aforementioned approaches. In this thesis, we summarize advancements in precision medicine in pediatric oncology. We present results of the Dutch precision-oncology program "iTHER", which analyzed over 300 samples of pediatric tumors and found alterations to support treatment with specific medicines. While the study produced promising results, translation to clinical practice has been limited by the low number of patients treated accordingly. Subgroups of patients with high-priority targets in a large international cohort are shown to benefit from targeted treatment. To support clinical decision making, a novel dataset of neuroblastoma organoids is presented including molecular and drug sensitivity features. Future developments will explore these new techniques, as well as liquid biopsies and immunotherapies, to improve the chances of children and young adults with cancer by more accurately diagnosing and treating tumors using precision medicine

Primary immunodeficiencies and their associated risk of malignancies in children: an overview.

Primary immunodeficiency disorders represent a heterogeneous spectrum of diseases, predisposing to recurrent infections, allergy, and autoimmunity. While an association between primary immunodeficiency disorders and increased risk of cancer has been suggested since the 1970s, renewed attention has been given to this topic in the last decade, largely in light of the availability of large registries as well as advances in next generation sequencing. In this narrative review, we will give an insight of the primary immunodeficiencies that are commonly responsible for the greater number of cancers in the primary immunodeficiency disorders population. We will describe clinical presentations, underlying genetic lesions (if known), molecular mechanisms for carcinogenesis, as well as some management considerations. We will also comment on the future directions and challenges related to this topic.Conclusion: The awareness of the association between several primary immunodeficiencies and cancer is crucial to provide the best care for these patients.What is Known: • Patients with primary immunodeficiency have an increased risk of malignancy. The type of malignancy is highly dependent on the specific primary immunodeficiency disorder.What is New: • Survival in patients with primary immunodeficiency disorders has been improving, and conversely also their lifetime risk of malignancy. • International collaboration and multinational registries are needed to improve our knowledge and therapeutic strategies

Tumor to normal single-cell mRNA comparisons reveal a pan-neuroblastoma cancer cell

Neuroblastoma is a childhood cancer that resembles developmental stages of the neural crest. It is not established what developmental processes neuroblastoma cancer cells represent. Here, we sought to reveal the phenotype of neuroblastoma cancer cells by comparing cancer (n = 19,723) with normal fetal adrenal single-cell transcriptomes (n = 57,972). Our principal finding was that the neuroblastoma cancer cell resembled fetal sympathoblasts, but no other fetal adrenal cell type. The sympathoblastic state was a universal feature of neuroblastoma cells, transcending cell cluster diversity, individual patients, and clinical phenotypes. We substantiated our findings in 650 neuroblastoma bulk transcriptomes and by integrating canonical features of the neuroblastoma genome with transcriptional signals. Overall, our observations indicate that a pan-neuroblastoma cancer cell state exists, which may be attractive for novel immunotherapeutic and targeted avenues

Tumor to normal single-cell mRNA comparisons reveal a pan-neuroblastoma cancer cell

Neuroblastoma is a childhood cancer that resembles developmental stages of the neural crest. It is not established what developmental processes neuroblastoma cancer cells represent. Here, we sought to reveal the phenotype of neuroblastoma cancer cells by comparing cancer (n = 19,723) with normal fetal adrenal single-cell transcriptomes (n = 57,972). Our principal finding was that the neuroblastoma cancer cell resembled fetal sympathoblasts, but no other fetal adrenal cell type. The sympathoblastic state was a universal feature of neuroblastoma cells, transcending cell cluster diversity, individual patients, and clinical phenotypes. We substantiated our findings in 650 neuroblastoma bulk transcriptomes and by integrating canonical features of the neuroblastoma genome with transcriptional signals. Overall, our observations indicate that a pan-neuroblastoma cancer cell state exists, which may be attractive for novel immunotherapeutic and targeted avenues