Overview of Pediatric Cancer

In the United States from 2001 through 2016, the overall incidence of cancer in children and adolescents increased by approximately 1% per year (1). Since 2016, the overall incidence has been declining at about the same rate. However, individual cancers, including thyroid cancer and adolescent leukemia/lymphoma, continue to increase in incidence (2).

From 1970 through 2020, deaths resulting from childhood and adolescent cancer have decreased between 64% and 70% (2).

Cancer is a major cause of pediatric mortality. In the United States, cancer is the second most common cause of death among children 1 to 14 years old (surpassed only by accidents) and is the fourth most common cause of death among adolescents 15 to 19 years old (2).

The most common cancers in children and adolescents (birth to age 19) include (2):

• Leukemia (representing approximately 28% of childhood cancer cases)

• Brain and other central nervous system tumors (27% of cases)

• Lymphomas (12% of cases)

• Osteosarcoma and Ewing sarcoma (3% of cases)

These cancers also occur in adults.

Cancers that occur almost exclusively in children (birth to age 14) include peripheral embryonal tumors that as a group comprise approximately 17% of childhood cancers (2):

• Neuroblastoma

• Wilms tumor (nephroblastoma)

• Rhabdomyosarcoma

• Retinoblastoma

Approximately 85% of children and adolescents with cancer survive at least 5 years (3). In the United States it is estimated that there are between approximately 400,000 and 500,000 survivors of childhood cancer (4, 5). However, children who survive cancer have more years than adults to develop long-term consequences of therapy, which may include (4, 6):

• Poor growth

• Delayed or absent puberty

• Infertility

• Cardiac damage

• Psychosocial effects

• Developmental and/or neurologic deficits

• Development of secondary cancers (20% cumulative incidence at 30 years after original diagnosis) (7)

Consensus guidelines on screening for and management of long-term consequences are available from the Children's Oncology Group.

Because of the severe consequences and complexity of treatment, children with cancer are best treated in centers with expertise in childhood cancers.

Treatment of childhood cancer depends on the type of cancer and on the stage, grade, and/or risk classification. Common treatments include:

• Chemotherapy

• Surgery

• Radiation therapy

• Stem cell transplantation

• Immunotherapy (including monoclonal antibodies, oncolytic virus therapy, cancer vaccines, chimeric antigen receptor (CAR) T-cell therapy, and bispecific T-cell engagers)

• Targeted therapies (therapies based on specific genetic mutations, which target proteins controlling proliferation and metastasis)

Children who are newly diagnosed with cancer should be evaluated for a cancer predisposition syndrome by a cancer genetics team. A cancer predisposition syndrome is a germline genetic mutation that increases the chances of developing cancer at an earlier age compared to the risk for the general population.

The psychosocial impact of being diagnosed with cancer and the intensity of the treatment may be overwhelming to the child and family. Maintaining a sense of normalcy for the child is difficult, especially given the need for frequent hospitalizations, outpatient visits, and potentially painful procedures. Overwhelming stress is typical as parents struggle to continue to work, be attentive to their other children, and still attend to the many needs of the child with cancer. The situation is even more difficult when the child is being treated at a specialty center far from home.