Childhood Cancers: Causes, Symptoms, Diagnosis and Treatment — Overview, Diagnosis & Treatment Options | MyMedicPlus

Childhood cancers are malignancies diagnosed in patients under age 15 (adolescent and young adult cancers extend to age 39 in some frameworks). They differ fundamentally from adult cancers in biology, etiology, and response to therapy. Approximately 400,000 children worldwide develop cancer annually; in the US, approximately 15,000 new pediatric cancer cases are diagnosed each year. The most common types are acute lymphoblastic leukemia (ALL, 25%), brain and CNS tumors (20%), neuroblastoma, Wilms tumor (nephroblastoma), lymphoma (Hodgkin and non-Hodgkin), retinoblastoma, and bone tumors (osteosarcoma and Ewing sarcoma). Modern risk-stratified treatment protocols delivered at specialist pediatric oncology centers have transformed outcomes: overall 5-year survival now exceeds 83% in high-income countries, compared to approximately 28% in the 1960s. Childhood cancer is now more commonly survived than not in high-income settings.

Unlike adult cancers, most childhood cancers arise from acquired de novo somatic mutations without an identifiable environmental trigger. Key genetic predisposition syndromes: Down syndrome (trisomy 21) confers a 10-20-fold increased risk of ALL and AML; Li-Fraumeni syndrome (TP53 germline) predisposes to osteosarcoma, rhabdomyosarcoma, medulloblastoma, and leukemia; NF1 predisposes to brain gliomas and leukemia; Beckwith-Wiedemann syndrome to Wilms tumor and hepatoblastoma; DICER1 mutations to pleuropulmonary blastoma; RB1 mutations to retinoblastoma; and SMARCB1 mutations to AT/RT. Prior ionizing radiation (therapeutic) significantly increases risk of secondary CNS, thyroid, and breast malignancies. EBV is associated with endemic Burkitt lymphoma and some Hodgkin lymphoma cases. No dietary or lifestyle factors are established causative agents for childhood cancers.

Warning signs vary by tumor type but should prompt urgent evaluation if persistent. Leukemia (ALL/AML) warning signs: unexplained pallor and fatigue (anemia), easy bruising or petechiae (thrombocytopenia), recurrent or persistent fever (neutropenia), lymphadenopathy, bone pain, and hepatosplenomegaly. Brain tumor warning signs: persistent morning headaches with or without vomiting (raised ICP), progressive gait instability or ataxia, behavioral or cognitive changes, and new seizures. Wilms tumor or neuroblastoma: an asymptomatic abdominal mass discovered by a parent during bathing or by a physician; associated hypertension (Wilms tumor). Bone sarcoma: persistent pain at a specific bone site (not generalizing to multiple joints), worse at night and not relieved by rest or NSAIDs. Lymphoma: painless progressive lymph node enlargement, mediastinal mass, night sweats, fever, and weight loss.

Acute leukemia: CBC with differential showing circulating blasts (not always present); bone marrow aspirate and trephine biopsy for morphology, flow cytometry (immunophenotype), cytogenetics (karyotype), and molecular profiling (BCR-ABL1, ETV6-RUNX1, MLL rearrangements, IKZF1, CRLF2) for risk stratification. CSF analysis for CNS disease. Solid tumor diagnosis: MRI with gadolinium (brain tumors, soft tissue tumors); CT and MIBG scan for neuroblastoma; Wilms tumor — MRI or CT abdomen with renal protocol. Bone marrow biopsy for leukemia staging. Bone scintigraphy and FDG-PET for lymphoma and bone tumors. Tumor markers: AFP (hepatoblastoma), beta-HCG (germ cell tumors), urinary catecholamines (VMA, HVA) for neuroblastoma, LDH, and NSE. Molecular profiling — NGS, RNA sequencing, DNA methylation array — now standard of care for all pediatric cancers.

Treatment is always multimodal, risk-stratified, and delivered at specialist pediatric oncology centers within clinical trials where possible. ALL: risk-stratified induction (vincristine, dexamethasone, asparaginase), consolidation, and 2-3 year maintenance (mercaptopurine, methotrexate); CNS-directed intrathecal therapy (methotrexate); tyrosine kinase inhibitors (dasatinib, imatinib) for Ph+ ALL; blinatumomab (bispecific T-cell engager) for relapsed/refractory; CAR-T cell therapy (tisagenlecleucel) for ≥2nd relapsed B-cell ALL achieves remission in approximately 80%. Brain tumors: surgical resection; craniospinal irradiation (medulloblastoma, ependymoma); risk-stratified chemotherapy; BRAF/MEK inhibitors for BRAF-altered low-grade gliomas. Neuroblastoma: high-risk disease — induction chemotherapy (ANBL1232), tandem autologous SCT, anti-GD2 immunotherapy (dinutuximab), isotretinoin maintenance. Wilms tumor: nephrectomy + chemotherapy (vincristine, actinomycin-D, doxorubicin); radiotherapy for advanced stages. Hodgkin lymphoma: ABVD or BEACOPP chemotherapy ± radiation — 5-year survival exceeds 95%.

Survival rates for childhood cancers in high-income countries have improved dramatically over six decades: overall 5-year survival now exceeds 83%, compared to approximately 28% in the 1960s. By cancer type: acute lymphoblastic leukemia (ALL) achieves 5-year OS exceeding 90% overall, and over 95% for favorable-risk (ETV6-RUNX1-positive, standard-risk) ALL. Hodgkin lymphoma: 5-year OS exceeding 95-97%. Wilms tumor (nephroblastoma): 5-year OS exceeding 90% across all stages; stage V bilateral disease approximately 82%. Retinoblastoma: 5-year OS exceeding 97%. Brain tumors: approximately 75% overall, but highly variable by histology — pilocytic astrocytoma after GTR exceeds 95%; WNT-activated medulloblastoma exceeds 95%; AT/RT less than 30%. High-risk neuroblastoma (MYCN-amplified, stage 4): 5-year OS less than 40-50% despite intensive multimodal therapy including immunotherapy. Osteosarcoma and Ewing sarcoma (localized): 5-year OS approximately 60-70%; metastatic at presentation: 5-year OS approximately 20-30%. Without treatment, childhood cancers are universally fatal within months to a few years. Key prognostic factors include cancer type and molecular subgroup, disease stage at diagnosis, tumor biology (ploidy, driver fusions, MYCN amplification), age at diagnosis, and response to initial induction therapy — early response is highly predictive across all pediatric cancer types. Long-term survivorship is critical: over 70% of childhood cancer survivors develop at least one chronic health condition. Long-term follow-up programs monitor for anthracycline cardiomyopathy, cisplatin sensorineural hearing loss, radiation-related neurocognitive impairment and endocrine dysfunction, secondary malignancies (cumulative 20-year risk approximately 3-4%), and infertility from alkylating agents.

Most childhood cancers are not preventable with current knowledge, as they arise from de novo somatic or germline mutations without established environmental triggers. Genetic counseling and germline testing of children with hereditary predisposition syndromes (Li-Fraumeni, NF1, Down syndrome, Beckwith-Wiedemann, RB1 mutations) enables surveillance programs that detect cancers at earlier, more curable stages. Avoiding unnecessary ionizing radiation exposure in children (unnecessary CT scans, excessive diagnostic X-rays) reduces secondary cancer risk. Universal childhood vaccination programs (HBV vaccine, which prevents HCC; and HPV vaccine, which prevents cervical cancer and other HPV-related malignancies detectable in adolescence) provide primary cancer prevention for virally associated cancers. Healthy lifestyle habits — maintaining healthy weight, regular physical activity, avoiding tobacco and alcohol exposure — reduce risk of adult cancers that may have roots in childhood exposures, even if their direct pediatric impact is limited.

Parents should seek urgent medical evaluation for a child who has: unexplained pallor, persistent fatigue, or lethargy; easy bruising, petechiae (small red dots under the skin), or prolonged bleeding; persistent fever lasting more than 7-10 days without clear infectious focus; painless progressive lymph node swelling that does not resolve within 4-6 weeks; persistent morning headaches with vomiting — especially in a child previously free of headaches; an abdominal mass felt incidentally; unsteady gait or progressive clumsiness; persistent localized bone pain worse at night; or unexplained weight loss. These are the cardinal warning signs of childhood cancer that warrant urgent investigation including blood count and specialist referral. Delays in pediatric cancer diagnosis are unfortunately common — parents should advocate for their child if symptoms persist despite initial reassurance.