About 80% of childhood cancer cases in high-income countries can be treated with modern treatments and good medical care. Although treatment and care are available, only 10% of children with cancer reside in high-income countries. Globally, children with cancer account for approximately 1% of all cancer diagnosis annually. The majority of children with cancer are in low- and middle-income countries, where it is responsible for 94% of deaths among those under 15 years old, because new cancer treatments are not easily available in these countries. For this reason, in low and mid-income countries, childhood cancer is often ignored in control planning, contributing to the burden of missed opportunities for its diagnoses and management.
Even with improved care, childhood cancer survivors face ongoing risks of recurrence and secondary cancers. Rates of childhood cancer deaths have steadily declined since 2003, but rates of pediatric cancer are on the rise. The biggest increase has been seen in thyroid carcinomas, lymphoma, and hepatic tumors. Pediatric cancer patients face additional challenges in education, income, and social support compared to the general population and their siblings.
In the United States, an arbitrarily adopted standard of the ages used is 0–14 years inclusive, up to age 14 years 11.9 months. However, the definition of childhood cancer sometimes includes adolescents between 15 and 19 years old. Pediatric oncology is the branch of medicine concerned with the diagnosis and treatment of cancer in children.
Signs and symptoms Common childhood malignancies can be categorized by the International Classification of Childhood Cancer (ICCC), which is a standardized method created by the World Health Organization (WHO). ICCC ClassificationInformationSigns and SymptomsI. Leukemias, Myeloproliferative And Myelodysplastic Diseases(a) Lymphoid leukemiasThis is the most common type of cancer during childhood, and acute lymphoblastic leukemia (ALL) is most common in children. ALL usually develops in children between the ages of 1 and 10 (it could occur at any age). This type of cancer is more prevalent in males and white people. Diagnosis is frequently delayed due to nonspecific early symptoms. Generalized malaise Loss of appetite Low-grade fever Pallor Petechiae Ecchymoses Bone pain Significant, unintended, and sudden weight loss Significant lymphadenopathy Hepatosplenomegaly(b) Acute myeloid leukemias(c) Chronic myeloproliferative diseases(d) Myelodysplastic syndrome and other myeloproliferative diseases(e) Unspecified and other specified leukemiasII. Lymphomas and reticuloendothelial neoplasms(a) Hodgkin lymphomasThe likelihood of developing Hodgkin Lymphoma increases during childhood and it peaks in adolescence. It is often associated with Epstein-Barr virus infection. Painless mass in the neck Persistent cough secondary to a mediastinal mass Less commonly: splenomegaly or enlarged axillary or inguinal lymph nodes Intermittent fever Drenching night sweats Loss of greater than 10 percent of total body weight Anorexia Fatigue Pruritus Persistent painless mass(b) Non-Hodgkin lymphomas (except Burkitt lymphoma)Non-Hodgkin's lymphoma is more common in older children, and it is less prevalent than Hodgkin's disease.If the abdomen is affected
Abdominal pain Vomiting or diarrhea Palpable mass and intussusception
If mediastinum is affected
Severe dyspnea Superior vena cava syndrome
If head and neck masses are affected
Palpable mass Cranial nerve palsies Nasal obstruction(c) Burkitt lymphoma(d) Miscellaneous lymphoreticular neoplasms(e) Unspecified lymphomasIII. CNS and Miscellaneous Intracranial and Intraspinal Neoplasms(a) Ependymomas and choroid plexus tumorCNS tumors are the second most common malignancy diagnosed during childhood, and they are the leading cause of death from cancer in children. Headache Nausea and vomiting Papilledema Bulging fontanelle Behavioral changes (lethargy, irritability, etc) Failure to thrive Ataxia Other gait disturbances (hydrocephalus due to aqueduct compression) Cranial nerve abnormalities as a result of brainstem compression(b) Astrocytomas(c) Intracranial and intraspinal embryonal tumors(d) Other gliomas(e) Other specified intracranial and intraspinal neoplasms(f) Unspecified intracranial and intraspinal neoplasmsIV. Neuroblastoma And Other Peripheral Nervous Cell Tumors(a) Neuroblastoma and ganglioneuroblastomaNeuroblastomas are the most common extracranial solid tumor in children. Dysfunction of the location of the primary tumor Anorexia Abdominal pain Distention(b) Other peripheral nervous cell tumorsV. RetinoblastomaRetinoblastomaRetinoblastomas typically affect children under 3 years old. Most children in resource-rich areas survive but they may lose vision in the affected eye. Leukocoria Vision loss StrabismusVI. Renal Tumors(a) Nephroblastoma and other non-epithelial renal tumorsNephroblastoma, also known as Wilm's tumor, represents the majority of cases of renal tumors in children. Hematuria Hypertension Abdominal mass Abdominal pain Fever(b) Renal carcinomas(c) Unspecified malignant renal tumorsVII. Hepatic Tumors(a) Hepatoblastoma and mesenchymal tumors of liverHepatic tumors are relatively rare in children, but are most commonly hepatoblastomas if they do occur. Jaundice Hepatomegaly Abdominal mass Nausea and vomiting Ascites Weight loss Appetite loss(b) Hepatic carcinomas(c) Unspecified malignant hepatic tumorsVIII. Malignant Bone Tumors(a) OsteosarcomasBone tumors in children typically arise in adolescence. These typically have a good prognosis with chemotherapy, radiation, and surgery if necessary. Localized bone pain Pathologic fractures with minimal trauma Difficulty bearing weight(b) Chondrosarcomas(c) Ewing tumor and related sarcomas of bone(d) Other specified malignant bone tumors(e) Unspecified malignant bone tumorsIX. Soft Tissue And Other Extraosseous Sarcomas(a) RhabdomyosarcomasSoft tissue sarcomas can form anywhere in the body as a cancer of the body's supporting tissues, including fat, muscle, and blood vessels. Localized mass Swelling or pain Limited range of motion Redness or warmth Skin changes (ulceration, discoloration)(b) Fibrosarcomas, peripheral nerve sheath tumors and other fibrous neoplasms(c) Kaposi sarcoma(d) Other specified soft tissue sarcomas(e) Unspecified soft tissue sarcomasX. Germ Cell Tumors, Trophoblastic Tumors And Neoplasms Of Gonads(a) Intracranial and intraspinal germ cell tumorsThese tumors arise from cells that eventually form sperm or eggs. They are often found in the gonads, but can travel to other parts of the body. Testicular or ovarian swelling Abdominal pain or fullness Virilization Precocious puberty Abnormal uterine bleeding(b) Malignant extracranial and extragonadal germ cell tumors(c) Malignant gonadal germ cell tumors(d) Gonadal carcinomas(e) Other and unspecified malignant gonadal tumorsXI. Other Malignant Epithelial Neoplasms And Malignant Melanomas(a) Adrenocortical carcinomasThese tumors are classified as functioning or non-functioning, depending on whether they produce adrenocortical hormone. Abdominal mass Hypertension Hyperglycemia Weight gain Hormone production Hirsutism Virilization Acne Gynecomastia(b) Thyroid carcinomasThyroid cancers include four main types: papillary, follicular, medullary, and anaplastic. Of these, papillary is the most common in children and anaplastic is rarely seen. Palpable mass on thyroid Lymphadenopathy Hoarseness(c) Nasopharyngeal carcinomasThis is a rare cancer which forms in the back of the nasal cavity in the throat. It is associated with Epstein-Barr virus infection. Lymphadenopathy Bleeding from the nose Facial numbness Headaches Sore throat(d) Malignant melanomasSkin cancers are rare in children due to less UV exposure, though may be seen in children with a family history of skin cancer or a genetic condition such as xeroderma pigmentosum. Skin changes (discoloration, ulceration, etc) Mole or freckle which is growing or changing color Pruritus(e) Skin carcinomas(f) Other and unspecified carcinomasXII. Other And Unspecified Malignant Neoplasms(a) Other specified malignant tumors(b) Other unspecified malignant tumors
Risk factors
Risk factors are any genetic or environmental exposure that increases the chances of developing a pathological condition. Some examples are age, family history, environmental factors, genetics, and economic status among others. Several chromosomal disorders and constitutional syndromes are also associated with childhood cancer.
Demographic risk factors Childhood cancer varies by age, sex, ethnicity, and race. Its incidence peaks in infancy with about 240 cases/million/year. This rate decreases to 128 cases per million from five–nine years of age, and it rises again to 220 cases/million. Slight male dominance for most childhood cancers.
Environmental factors High-dose ionizing radiation and certain forms of prior chemotherapy are established risk factors for childhood cancer, each increasing cancer risk severalfold.
Genetic factors Identified Cancer Predisposition Syndromes
Li–Fraumeni syndrome (TP53) Hereditary breast or ovarian cancer (BRCA ) Colorectal cancer/polyposis syndromes Familial retinoblastoma (RB1) Familial and genetic factors are identified in 5–15% of childhood cancer cases. In <5–10% of cases, there are known environmental exposures and exogenous factors, such as prenatal exposure to tobacco, X-rays, or certain medications. In turn citing: For the remaining 75–90% of cases, however, the individual causes remain unknown. In most cases, as in carcinogenesis in general, the cancers are assumed to involve multiple risk factors and variables. In turn citing: >
Aspects that make the risk factors of childhood cancer different from those seen in adult cancers include: Different, and sometimes unique, exposures to environmental hazards. Children must often rely on adults to protect them from toxic environmental agents. Immature physiological systems to clear or metabolize environmental substances The growth and development of children in phases known as "developmental windows" result in certain "critical windows of vulnerability". Also, a longer life expectancy in children allows for a longer time to manifest cancer processes with long latency periods, increasing the risk of developing some cancer types later in life.
Advanced parental age has been associated with an increased risk of childhood cancer in the offspring. There are preventable causes of childhood malignancy, such as delivery overuse and misuse of ionizing radiation through computed tomography scans when the test is not indicated or when adult protocols are used.
Diagnosis
Types The most common childhood cancers (birth – 14 years old) are leukemia (28%), central nervous system tumors (27%), and lymphomas (12%). The main subtypes of brain and central nervous system tumors in children are: astrocytoma, brain stem glioma, craniopharyngioma, desmoplastic infantile ganglioglioma, ependymoma, high-grade glioma, medulloblastoma and atypical teratoid rhabdoid tumor. In 2020–2022, 1.9 per 100,000 children died from cancer.
In 2022, an estimated 4.2 per 100,000 individuals in the United States younger than 20 years were diagnosed with leukemia, and 0.6 per 100,000 died from the disease. In the same year, 2.3 per 100,000 individuals in this age group were diagnosed with cancers of the brain or central nervous system, and 0.6 per 100,000 died from these tumors. The incidence of both leukemia and brain or central nervous system cancers in children and adolescents has declined since 2016 and 2018, respectively.
Other, less common childhood cancer types are: Neuroblastoma (6%, nervous system) Wilms tumor (5%, kidney) Non-Hodgkin lymphoma (4%, blood) Childhood rhabdomyosarcoma (3%, many sites) Retinoblastoma (3%, eye)