Cancer in Children and Adolescents
How common is cancer in children and adolescents?
Although cancer in children and adolescents is rare, it is the leading cause of death by disease past infancy among children in the United States. In 2021, it is estimated that 15,590 children and adolescents ages 0 to 19 will be diagnosed with cancer and 1,780 will die of the disease in the United States (1). Among children ages 0 to 14 years, it is estimated that in 2021, 10,500 will be diagnosed with cancer and 1,190 will die of the disease (1). Among adolescents ages 15 to 19 years, about 5,090 will be diagnosed with cancer and about 590 will die of the disease.
Among adolescents (ages 15 to 19 years), the most common types of cancer are brain and other CNS tumors and lymphomas, followed by leukemias, thyroid cancer, gonadal (testicular and ovarian) germ cell tumors, and malignant bone tumors (1).
Different racial and ethnic groups have differences in rates of the most common types of childhood cancer. For example, in 2013–2017, among children ages 0 to 14, Hispanic children had nearly twice the rate of leukemia as Black children (2). In 2014–2018, rates of brain and other CNS tumors were higher in White children than all other racial and ethnic groups (3, 4).
As of January 1, 2018 (the most recent date for which data exist), approximately 483,000 survivors of childhood and adolescent cancer (diagnosed at ages 0 to 19 years) were alive in the United States (5). The number of survivors will continue to increase, given that the incidence of childhood cancer has been rising slightly in recent decades and that survival rates overall are improving.
What is the prognosis for children and adolescents with cancer?
The overall outlook for children and adolescents with cancer has improved greatly over the last half-century. In the mid-1970s, 58% of children (ages 0 to 14 years) and 68% of adolescents (ages 15 to 19 years) diagnosed with cancer survived at least 5 years (1). In 2011–2017, 84.7% of children and 85.9% of adolescents diagnosed with cancer survived at least 5 years (5).
Although survival rates for most childhood cancers have improved in recent decades, the improvement has been especially dramatic for a few cancers, particularly acute lymphoblastic leukemia, the most common childhood cancer. Improved treatments introduced beginning in the 1960s and 1970s raised the 5-year survival rate for children diagnosed with acute lymphoblastic leukemia at ages 0 to 14 years from 57% in 1975 to 92% in 2012 (6). The 5-year survival rate for children diagnosed with non-Hodgkin lymphoma at ages 0 to 14 years also increased dramatically, from 43% in 1975 to 91% in 2012 (6).
Because of these survival improvements, brain cancer has replaced leukemia as the leading cause of cancer death among children (7). During 2001–2018, death rates among children from brain and other nervous system cancers were stable while death rates from leukemia declined an average of 2.9% per year (2).
In contrast, survival rates remain poor for some cancer types, for some age groups, and for some cancers within a site. For example:
- Half of children with diffuse intrinsic pontine glioma (a rare type of brain tumor) survive less than 1 year from diagnosis, and only 10% survive 2 years from diagnosis (8).
- Among children with Wilms tumor (a type of kidney cancer), older children (those diagnosed between ages 10 and 16 years) have lower 5-year survival rates than younger children (9).
- For soft tissue sarcomas, 5-year survival rates in 2011–2017 among children and adolescents ages 0 to 19 years ranged from 66% (rhabdomyosarcoma) to 73.7% (soft tissue and other extraosseous sarcomas) (5).
- In 2011–2017 the 5-year survival rate for lymphoid leukemia (mostly acute lymphoblastic leukemia) was 91.5% for children younger than 15 years, compared with 76% for adolescents ages 15 to 19 years (5).
Evidence suggests that adolescents and young adults with acute lymphoblastic leukemia may have better outcomes if they are treated with pediatric treatment regimens than if they receive adult treatment regimens (10). Recent improvements in 5-year survival rates for adolescents and younger adults with acute lymphoblastic leukemia (4) may reflect greater use of these pediatric treatment regimens.
The cancer mortality rate—the number of deaths due to cancer per 100,000 people per year—among children and adolescents ages 0 to 19 years declined by more than 50% from 1975 to 2018 (4). Specifically, the mortality rate was 5.1 per 100,000 children and adolescents in 1975 and 2.2 per 100,000 children and adolescents in 2018. However, despite the overall decrease in mortality, approximately 1,800 children and adolescents still die of cancer each year in the United States, indicating that new advances and continued research to identify effective treatments are required to further reduce childhood cancer mortality.
From 1997 through 2017, the cancer death rate dropped the most for 15- to 19-year-olds (a 1.7% drop each year on average), followed by that for 0- to-4-year-olds (a 1.4% drop each year), 10- to 14-year-olds (a 1.2% drop each year), and 5- to 9-year-olds (a 1.1% drop each year) (11).
What are the possible causes of cancer in children and adolescents?
Most cancers in children, like those in adults, have alterations (changes, or mutations) in genes that lead to uncontrolled cell growth and eventually cancer. Genetic changes (or variants) that are passed from parents to their children—known as germline variants—can be associated with an increased risk of cancer. Genetic changes that lead to cancer can also occur spontaneously in cells during development.
About 6% to 8% of all cancers in children overall are caused by an inherited pathogenic variant (harmful alteration) in a cancer predisposition gene, although the percentage varies across cancer types (12, 13). For example, about 45% of children with retinoblastoma, a cancer of the eye that develops mainly in children, inherited a pathogenic variant in a gene called RB1 from a parent (14). Children who inherit variants associated with certain familial syndromes, such as Li-Fraumeni syndrome, Beckwith-Wiedemann syndrome, Fanconi anemia, Noonan syndrome, and von Hippel-Lindau syndrome, also have an increased risk of childhood cancer.
Genomic changes that arise during development of one of the germ cells (sperm or egg) that unite to form the zygote that becomes a child can increase the risk of cancer in that child. Genomic changes can include broken, missing, rearranged, or extra chromosomes as well as gene variants. One such alteration is trisomy 21, or the presence of an extra copy of chromosome 21, which causes Down syndrome. Children with Down syndrome are 10 to 20 times more likely to develop leukemia than children without Down syndrome (15). However, only a very small proportion of childhood leukemia is linked to Down syndrome.
Genetic changes that sometimes can be associated with cancer can also occur in different cells of the body after birth, as the body is actively growing and developing during early childhood (16). The extent to which these changes reflect environmental exposures is unclear. In adults, exposure to cancer-causing substances in the environment, such as cigarette smoke, asbestos, and ultraviolet (UV) radiation from the sun is known to cause genetic changes that can lead to cancer. However, environmental causes of childhood cancer have been particularly difficult to identify, partly because cancer in children is rare and partly because it is difficult to determine what children might have been exposed to early in their development.
Nevertheless, several environmental exposures have been linked to childhood or adolescent cancer. For example, one study found that melanoma in children and adolescents (ages 11–20 years) has many genomic similarities to melanoma that occurs in adults, including an enrichment of UV-induced mutations (17). And ionizing radiation can lead to the development of leukemia and other cancers in children and adolescents. Children and adolescents who were exposed to radiation from the atomic bombs dropped in Japan during the Second World War had an elevated risk of leukemia (18), and children who were exposed to radiation from the Chernobyl nuclear plant accident had an elevated risk for thyroid cancer (19).
Exposure of parents to ionizing radiation is also a possible concern in terms of the development of cancer in their future offspring. Children whose mothers had x-rays during pregnancy (that is, children who were exposed before birth) and children exposed after birth to diagnostic medical radiation from computed tomography (CT) scans have been found to have a slight increase in risk of leukemia and brain tumors, and possibly other cancers (20). However, genomic analysis of children born to people exposed to radiation at Chernobyl indicates that this exposure did not lead to an increase in new genetic changes being passed from parent to child (21).
Several other environmental exposures have also been associated with childhood cancer. However, because of challenges in studying these associations, such as the difficulty of determining the specific chemical exposures at the relevant period in a child’s development, it is difficult to draw firm conclusions. For some types of childhood leukemia (particularly acute lymphoblastic leukemia), associations have been described for father’s tobacco smoking (22, 23); for exposure to certain pesticides used in and around the home (24) or by parents at their workplace (25, 26); for solvents, organic chemicals that are found in some household products; and for outdoor air pollution. Studies of childhood brain tumors have suggested associations with exposures to pesticides in and around the home (27) and maternal consumption of cured meats (28).
Researchers have also identified factors that may be associated with reduced risk of childhood cancer. For example, maternal consumption of folate has been associated with reduced risks of both leukemia and brain tumors in children (29). Being breastfed and having been exposed to routine childhood infections are both associated with a lowered risk of developing childhood leukemia (30).
What does a child’s cancer diagnosis mean for cancer risk in the rest of the family?
First- and second-degree relatives of a child diagnosed with cancer may be at increased risk for developing cancer if there is already a family history of cancer—that is, if the child’s cancer is likely due to an inherited genetic disorder (31). A clinician may advise as to whether a child and family members could benefit from genetic testing or referral to a medical geneticist or cancer genetic counselor for evaluation (31–33).
How do cancers in adolescents and young adults differ from those in younger children?
Cancer occurs more frequently in adolescents and young adults ages 15 to 39 years than in younger children, although incidence in this group is still much lower than in older adults. According to the NCI Surveillance, Epidemiology, and End Results (SEER) Program (4), each year in 2014–2018 there were:
- 17.8 cancer diagnoses per 100,000 children ages younger than 15 years
- 77.4 cancer diagnoses per 100,000 adolescents and young adults ages 15 to 39 years
- 548.9 cancer diagnoses per 100,000 adults ages 40 to 64 years
The most frequent cancers diagnosed in adolescents and young adults (AYAs) are cancers that are more common among adults than younger children, such as breast cancer, melanoma, and thyroid cancer (34). But certain cancers, such as testicular cancer, are more likely to be diagnosed among AYAs than among either younger children or adults (4). However, the incidence of specific cancer types varies widely across the adolescent and young adult age continuum.
Where do children and adolescents with cancer get treated?
Children and adolescents who have cancer are often treated at a children’s cancer center, which is a hospital or a unit within a hospital that specializes in diagnosing and treating patients through 20 years of age. The health professionals at these centers have specific training and expertise to provide comprehensive care for children and adolescents with cancer, and their families.
Children’s cancer centers also participate in clinical trials. The improvements in survival for children with cancer that have occurred over the past half century have been achieved because of treatment advances that were studied and proven to be effective in clinical trials.
More than 90% of children and adolescents who are diagnosed with cancer each year in the United States are cared for at a children’s cancer center that is affiliated with the NCI-supported Children’s Oncology Group (COG). COG is the world’s largest organization that performs clinical research to improve the care and treatment of children and adolescents with cancer. Each year, approximately 4,000 children who are diagnosed with cancer enroll in a COG-sponsored clinical trial. COG trials are sometimes open to older individuals when the type of cancer being studied is one that occurs in children, adolescents, and young adults.
Children’s cancer centers that participate in COG must meet and maintain strict standards of excellence for childhood cancer care. A directory of COG locations is available on their website. Families can ask their pediatrician or family doctor for a referral to a children’s cancer center. Families and health professionals can call NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237) to learn more about children’s cancer centers that belong to COG.
If my child is treated at a children’s cancer center, will they automatically be part of a clinical trial?
Can children and adolescents who have cancer be treated at the National Institutes of Health (NIH) Clinical Center?
Children and adolescents with cancer may be eligible to be treated in clinical trials at the NIH Clinical Center in Bethesda, Maryland. Because the NIH Clinical Center is a research hospital, only patients who have a specific type or stage of cancer that is under study can be accepted for treatment. In some cases, patients with conditions that are rare or difficult to diagnose may also be accepted for treatment at the NIH Clinical Center. All patients who are treated at the NIH Clinical Center must be referred by a physician.
NCI’s Pediatric Oncology Branch conducts clinical trials at the NIH Clinical Center for children, adolescents, and young adults with a wide variety of cancers. Patients with newly diagnosed cancer, as well as patients whose cancers have come back after treatment, may be eligible to participate in a clinical trial. Physicians at the Pediatric Oncology Branch can also provide a second opinion on a patient’s diagnosis or treatment plan. To refer a patient to the Pediatric Oncology Branch, the patient’s health care provider should call 301-496-4256 (local) or 1-877-624-4878 (toll-free) weekdays between 8:30 a.m. and 5:00 p.m. ET. Parents can also call these numbers to learn if their child is eligible to participate in a clinical trial.
NCI’s Clinical Genetics Branch conducts long-term observational and clinical studies of genetic susceptibility to cancer, mostly in families with a known or suspected cancer predisposition syndrome, or families that have a higher-than-expected rate of cancer. Although some of these study participants, including children and adolescents, are seen at the NIH Clinical Center, the genetic susceptibility studies do not evaluate treatment or other interventions, as in a clinical trial. Information about active studies that enroll children and adolescents can be obtained by contacting the referral nurse at 1-800-518-8474.
What should survivors of childhood and adolescent cancer consider after they complete treatment?
People who have had cancer during childhood or adolescence need follow-up care and enhanced medical surveillance for the rest of their lives because of the risk of complications related to the disease or its treatment that can last for, or arise, many years after they complete treatment for their cancer (35). Health problems that develop months or years after treatment has ended are known as late effects.
The specific late effects that a person who was treated for childhood cancer might experience depend on the type and location of their cancer, the type of treatment they received, and patient-related factors, such as age at diagnosis. Some people with a history of childhood cancer may need additional follow-up if an inherited genetic alteration is found to be the cause of the cancer.
Children and adolescents who were treated for bone cancer, brain tumors, or Hodgkin lymphoma, or who received radiation to their chest, abdomen, or pelvis, have the highest risk of serious late effects from their cancer treatment, including second cancers, joint replacement, hearing loss, and congestive heart failure (36–38).
Long-term follow-up analysis of a cohort of survivors of childhood cancer treated between 1970 and 1986 has shown that these survivors remain at risk of complications and premature death as they age, with more than half of them having experienced a severe or disabling complication or even death by the time they reach age 50 years (39). Children and adolescents treated in more recent decades may have lower risks of late effects due to modifications in treatment regimens to reduce exposure to radiotherapy and chemotherapy, increased efforts to detect late effects, and improvements in medical care for late effects (38, 40, 41).
It’s important for people who had cancer during childhood or adolescence to have regular medical follow-up examinations so any health problems can be identified and treated as soon as possible. The Children’s Oncology Group (COG) has developed long-term follow-up guidelines for survivors of childhood, adolescent, and young adult cancers.
It is also important to keep a record of the details of the cancer diagnosis and the treatment that was received. This record should include:
- the type and stage of cancer
- date of cancer diagnosis and dates of any relapses
- genetic testing for inherited variants and somatic (tumor) variants
- types and dates of imaging tests
- contact information for the hospitals and doctors who provided treatment
- names and total doses of all chemotherapy drugs used in treatment
- the parts of the body that were treated with radiation and the total doses of radiation that were given
- types and dates of all surgeries
- any other cancer treatments received
- any serious complications that occurred during treatment and how those complications were treated
- the date that cancer treatment was completed
The record should be kept in a safe place, and copies of the record should be given to all doctors or other health care providers who are involved with the child’s follow-up care, even as the child grows into adulthood.
Many children’s cancer centers have clinics where survivors of childhood cancer can go for follow-up care until they reach their early 20s. Some cancer centers are now creating clinics dedicated to follow-up care for long-term survivors of pediatric and adolescent cancers.
Many cancer centers also include programs to help families navigate long-term survivor care, including both the physical and emotional issues they may face after treatment. In addition, many adolescent and young adult (AYA) cancer programs have been created to address some of the more unique needs of teens and young adults. Areas of focus include discussing and preserving future fertility, peer support, and psychosocial support that addresses personal issues such as finances, education, occupational impacts, and transition to independence.