Pediatric Cancers

An Overview of Types, Diagnosis, and Treatment

Cancer involves abnormal cells growing uncontrollably, invading nearby tissues, and spreading to other parts of the body through metastasis. 

We're Here to Help.
Get in Touch.

Send us all your questions or requests, and our expert team will assist you.

Doctors

Pediatric Cancers

Pediatric Cancers

Pediatric oncology is a unique branch of medicine that differs from adult oncology in several key ways, including the origins and biology of the cancers. Adult cancers often develop over time due to environmental exposures and aging, leading to carcinomas. In contrast, most pediatric cancers are related to problems in early development. These cancers start when the normal process of organ and cell development goes wrong, causing immature cells to keep dividing instead of maturing into their proper roles. Understanding this difference is crucial for how we diagnose, treat, and manage cancer in children.

Pediatric cancers often look more like fetal tissue than adult tissue under the microscope. Many are called small, round, blue cell tumors because of their appearance, which shows they are made of immature cells. These tumors grow quickly, unlike most adult cancers, because the signals that should stop cell growth after birth stay active. While this fast growth makes the disease aggressive, it also means these cancers respond well to treatments that target dividing cells, which helps explain why cure rates in children are often higher than in adults.

Pediatric cancers have a different genetic profile compared to adult cancers. Adult tumors usually have many mutations built up over years, but childhood cancers often have only a few key genetic changes. These changes, like chromosomal translocations or gene amplifications (for example, MYCN), act as strong triggers that keep cells growing. Because of this, doctors can use more precise molecular tests to diagnose and plan treatment for pediatric cancers, rather than relying only on where the tumor is in the body.

Icon LIV Hospital

Embryonal Origins and Developmental Arrest

Embryonal Origins and Developmental Arrest

The pathogenesis of many pediatric cancers is rooted in the concept of developmental arrest. During embryogenesis, pluripotent stem cells differentiate through a hierarchy of progenitors to form specific organs. In pediatric oncology, a specific progenitor cell often sustains a genetic hit that prevents it from completing this differentiation program. The cell remains stuck in a proliferative, embryonic stage, expanding clonally to form a tumor. For instance, Wilms tumor represents a failure of the nephrogenic blastema to differentiate into renal tubules and glomeruli, while retinoblastoma results from the arrest of retinal progenitor differentiation.

This way of thinking changes the focus from just removing the tumor to understanding why the cells stopped maturing. Treatments like regenerative medicine and differentiation therapy try to help these cancer cells finish developing into normal, healthy cells. This approach shows that pediatric oncology is as much about understanding development as it is about treating cancer.

  • Blastemal cells are multipotent progenitors found in embryonic tissues that serve as the cell of origin for many pediatric solid tumors and retain the capacity for rapid division.
  • The concept of maturation arrest explains why pediatric tumors often express markers of early fetal development, such as alpha fetoprotein or specific embryonic surface antigens.
  • Neuroectodermal tumors arise from the neural crest cells, a transient migratory cell population known for its plasticity and ability to form diverse tissues, including the adrenal medulla and sympathetic ganglia.
  • Mesenchymal neoplasms, including rhabdomyosarcoma and osteosarcoma, derive from the primitive connective tissue precursors that form muscle, bone, and cartilage.
  • Epigenetic dysregulation plays a more significant role than somatic mutation in many pediatric cancers, silencing tumor suppressor genes without altering the DNA sequence.
Icon 1 LIV Hospital

The Genomic Landscape of Childhood Malignancy

The Genomic Landscape of Childhood Malignancy

The genomic architecture of pediatric cancer is characterized by specific, recurrent structural variations rather than the point mutations common in adults. Chromosomal translocations, where parts of two chromosomes break and fuse, create novel fusion proteins that function as potent oncogenes. These fusion oncoproteins act as master regulators, reprogramming the cell’s transcriptional machinery to maintain a stem-cell-like state. The EWS-FLI1 fusion in Ewing Sarcoma is a prototypical example in which the fusion protein aberrantly activates targets that drive cell proliferation and survival.

Furthermore, the role of germline predisposition is significantly more pronounced in the pediatric population. It is estimated that at least ten percent of children with cancer have an underlying cancer predisposition syndrome, such as Li-Fraumeni syndrome or Beckwith-Wiedemann syndrome. These syndromes involve germline mutations in critical tumor-suppressor genes, such as TP53, or growth-regulatory genes. Understanding this germline context is essential not only for treating the index patient but also for patient surveillance and surveillance of the patient’s family members.

  • Chromosomal translocations create fusion oncogenes that are unique to the tumor cells, providing ideal targets for molecularly specific therapies and diagnostic testing.
  • Copy number variations, such as the amplification of the MYCN gene in neuroblastoma, serve as powerful prognostic indicators determining the aggressiveness of the therapy required.
  • Chromothripsis or chromosome shattering is a catastrophic event seen in some pediatric brain tumors where a chromosome is shattered and reassembled randomly, leading to massive genomic rearrangement.
  • Germline mutations in TP53 are the hallmark of Li Fraumeni syndrome, predisposing children to a broad spectrum of malignancies, including adrenocortical carcinoma and choroid plexus carcinoma.
  • Epigenetic modifiers, such as the SWI/SNF chromatin remodeling complex, are frequently mutated in pediatric rhabdoid tumors, leading to global deregulation of gene expression.

Systemic Physiological Impact on the Growing Organism

Systemic Physiological Impact on the Growing Organism

Pediatric cancer affects the whole body of a growing child. Unlike adult cancer care, which often focuses on saving what organ function remains, pediatric oncology must consider how both the disease and its treatment affect the child’s ongoing growth and development. Fast-growing tissues like bone marrow, growth plates, and the developing brain are especially at risk.

Cancer itself can cause changes throughout a child’s body. For example, leukemia can damage the bone marrow, leading to anemia and a weak immune system even before any treatment starts. Some solid tumors release hormones or other substances that affect growth and metabolism. As a result, a child with cancer has high nutritional needs, but the tumor also uses up energy, making it harder for the child to grow normally.

  • Hematopoietic insufficiency results from the physical crowding out of normal stem cells by leukemic blasts or metastatic infiltrates in the bone marrow.
  • Osteopenia and growth failure can occur due to direct invasion of bone by malignancy or to systemic effects of inflammatory cytokines on growth plate chondrocytes.
  • Paraneoplastic syndromes such as opsoclonus myoclonus ataxia syndrome in neuroblastoma involve an autoimmune attack on the developing cerebellum triggered by cross-reactive tumor antigens.
  • Endocrine disruption is common, as tumors of the central nervous system can impinge on the hypothalamus or pituitary gland, altering the secretion of growth hormone and gonadotropins.
  • Cardiovascular stress is induced not only by the tumor’s metabolic demand but also by the anemia and fluid shifts associated with the malignancy, requiring careful hemodynamic monitoring.

Global Biotechnological Paradigms

The management of pediatric cancer is at the forefront of global biotechnology, particularly in the realms of immunotherapy and precision medicine. The field has moved beyond the era of non-specific chemotherapy to the era of targeted cellular engineering. Chimeric Antigen Receptor (CAR) T-cell therapy represents a paradigm shift in which the patient’s own immune cells are genetically modified ex vivo to express a receptor that recognizes a specific antigen on leukemia cells. This “living drug” has revolutionized the treatment of refractory acute lymphoblastic leukemia.

Concurrently, the integration of next-generation sequencing into routine clinical care enables molecular profiling of every tumor. This “precision oncology” approach seeks to match specific genomic alterations with targeted inhibitors, regardless of the histological tumor type. Liquid biopsies, which detect circulating tumor DNA in the blood, are emerging as non-invasive tools for monitoring treatment response and detecting relapse earlier than radiographic imaging.

  • CAR T cell therapy uses genetically engineered autologous T cells to target surface antigens such as CD19, initiating a potent and specific cytotoxic response against malignant B cells.
  • Antibody-drug conjugates combine the specificity of monoclonal antibodies with the potency of cytotoxic payloads, delivering chemotherapy directly to tumor cells while sparing normal tissues.
  • Liquid biopsy technologies analyze circulating tumor DNA to provide real-time insights into clonal evolution and the emergence of resistance mutations without invasive procedures.
  • Proteomic profiling complements genomic analysis by examining the functional proteins active in the tumor cell, identifying drug targets that might be missed by DNA sequencing alone.
  • Bioinformatics and artificial intelligence are essential for interpreting the massive datasets generated by genomic profiling to identify actionable targets and predict therapeutic responses.

Classification and Histological Diversity

The classification of pediatric cancers is distinct from that of adults, dominated by leukemias, brain tumors, and sarcomas rather than epithelial carcinomas. Acute Lymphoblastic Leukemia (ALL) is the most common malignancy, originating from lymphocyte precursors. Central nervous system tumors form the second largest group, ranging from low-grade gliomas to highly aggressive medulloblastomas. Extracranial solid tumors include neuroblastoma (sympathetic nervous system), Wilms tumor (kidney), rhabdomyosarcoma (muscle), and osteosarcoma (bone).

Each of these categories is further subdivided based on histology and molecular features. For example, medulloblastoma is no longer treated as a single entity. Still, it is stratified into four distinct molecular subgroups (WNT, SHH, Group 3, and Group 4), each with a different prognosis and treatment protocol. This granular classification ensures that therapy is tailored to the tumor’s specific biology, maximizing cure rates while minimizing toxicity.

  • Acute Lymphoblastic Leukemia is the predominant pediatric malignancy characterized by the overproduction of immature lymphocytes in the bone marrow and lymphoid organs.
  • Central Nervous System tumors include a diverse group of neoplasms such as astrocytomas, medulloblastomas, and ependymomas arising from glial or neuronal precursors.
  • Neuroblastoma is an extracranial solid tumor of the sympathetic nervous system, most commonly arising in the adrenal gland and characterized by its heterogeneity and variable clinical course.
  • Wilms tumor or nephroblastoma is a kidney tumor derived from primitive metanephric blastema, often presenting as an asymptomatic abdominal mass in young children.
  • Soft tissue and bone sarcomas such as rhabdomyosarcoma and Ewing sarcoma are malignancies of mesenchymal origin requiring complex multimodal therapy including surgery and radiation

30
Years of
Excellence

Trusted Worldwide

With patients from across the globe, we bring over three decades of medical expertise and hospitality to every individual who walks through our doors.  

Book a Free Certified Online Doctor Consultation

Doctors

Table of Contents

We're Here to Help.
Get in Touch.

Send us all your questions or requests, and our expert team will assist you.

Doctors

FREQUENTLY ASKED QUESTIONS

What is the fundamental difference between pediatric and adult cancer?

Pediatric cancers are primarily embryonal or developmental in origin, arising from primitive cells that fail to mature. In contrast, adult cancers are typically carcinomas arising from epithelial tissues, driven by cumulative environmental damage and aging. This biological difference means pediatric cancers often grow faster but are more responsive to chemotherapy.

This term describes the microscopic appearance of many pediatric cancers, such as neuroblastoma and lymphoma. These cells appear this way because they are primitive, undifferentiated cells with large nuclei and minimal cytoplasm, reflecting their embryonic nature and rapid rate of division.

A germline mutation is a genetic alteration present in the egg or sperm that is passed down to the child and exists in every cell of their body. In pediatric oncology, these mutations predispose the child to developing cancer, as seen in syndromes like Li-Fraumeni or Retinoblastoma, unlike somatic mutations, which occur only in the tumor cells.

Developmental arrest occurs when a primitive stem or progenitor cell becomes stuck at an immature stage and continues to divide rather than maturing into a functional cell. This population of immature, dividing cells accumulates to form a tumor, which is the underlying mechanism in many pediatric malignancies, such as Wilms’ tumor.

Fusion oncogenes form when parts of two chromosomes break and fuse, a process standard in pediatric cancers such as Ewing Sarcoma. These fusion genes produce abnormal proteins that act as powerful drivers of cancer cell growth and serve as specific targets for diagnosis and, potentially, new therapies.

Spine Hospital of Louisiana