Overview of Pediatric Cancer

In the United States, the overall incidence of cancer in children and adolescents has increased over time. From 1975 to 2022, rates increased by approximately 0.8 per 100,000 each year. However, death rates decreased from 1970 through 2020 by 70% in children (from 6.3 to 1.9 per 100,000) and by 64% in adolescents (from 7.2 to 2.6 per 100,000) (1). In 2024, approximately 10,000 cases of cancer are expected to be diagnosed among children from birth to 14 years old and approximately 5,300 cases of cancer are expected to be diagnosed among adolescents 15 to 19 years old (1).

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 (1).

Many of the most common cancers that occur in children or adolescents (birth to age 14) can also occur in adults. These include (1)

• Leukemia, the most common pediatric cancer (representing approximately 28% of childhood cancer cases)

• Brain and other central nervous system tumors (25% of cases)

• Lymphomas (12% of cases)

• Osteosarcoma and Ewing sarcoma (4% of cases)

Cancers that occur exclusively in children (birth to age 14) include

• Neuroblastoma

• Wilms tumor

• Rhabdomyosarcoma

• Retinoblastoma

Approximately 85% of children and adolescents with cancer survive at least 5 years (2). In the United States in 2020, it was estimated that there were 496,000 survivors of childhood cancer (ie, first diagnosed before age 20) (3). Children who survive cancer have more years than adults to develop long-term consequences of chemotherapy, surgery, and radiation therapy, which may include

• Poor growth

• Delayed or absent puberty

• Infertility

• Cardiac damage

• Psychosocial effects

• Developmental and/or neurologic deficits

• Development of secondary cancers (in 3 to 12% of survivors, varying with their initial cancer and type of treatment)

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, and stem cell transplantation.

Immunotherapy is a type of treatment that helps the person's own immune system attack the cancer and may be helpful for certain childhood cancers. Different types of immunotherapy include monoclonal antibodies, oncolytic virus therapy, cancer vaccines, chimeric antigen receptor (CAR) T-cell therapy, and bispecific T-cell engagers. CD19 CAR T-cell therapy is used in pediatric pre-B cell acute lymphoblastic leukemia.

In addition, targeted therapy is a treatment approach that has been developed to target proteins that control how cancer cells proliferate and metastasize. These therapies typically target a specific genetic mutation and are the foundation of precision medicine. Several different kinds of targeted therapy are used in pediatric cancers with specific mutations. Some examples of targeted therapy include imatinib for the treatment of chronic myeloid leukemia, larotrectinib for the treatment of solid tumors with In addition, targeted therapy is a treatment approach that has been developed to target proteins that control how cancer cells proliferate and metastasize. These therapies typically target a specific genetic mutation and are the foundation of precision medicine. Several different kinds of targeted therapy are used in pediatric cancers with specific mutations. Some examples of targeted therapy include imatinib for the treatment of chronic myeloid leukemia, larotrectinib for the treatment of solid tumors withNTRK gene fusions, and dabrafenib/trametinib for low-grade gliomas with BRAFV600E mutations. gene fusions, and dabrafenib/trametinib for low-grade gliomas with BRAFV600E mutations.

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 siblings, 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.