Childhood Cancer: Introduction

Approved by the Cancer.Net Editorial Board, 09/2019

ON THIS PAGE: You will find some basic information about this disease and the parts of the body it may affect. This is the first page of Cancer.Net’s Guide to Childhood Cancer. Use the menu to see other pages. Think of that menu as a roadmap for this complete guide.

Cancer is uncommon in children. Most cancers (99%) develop in adults, and it is most common in older adults. About 1 out of every 3 adults will develop cancer during his or her lifetime, while about 1 in 285 children will develop cancer before the age of 20.

At the same time, there is a lot of research going on to discover new treatments for childhood cancer. This research has greatly improved the overall survival rate for children with cancer, which is now more than 80%.

What is childhood cancer?

Cancer in children can occur anywhere in the body, including the blood and lymph node systems, brain and spinal cord (central nervous system; CNS), kidneys, and other organs and tissues.

Cancer begins when healthy cells change and grow out of control. In most types of cancer, these cells form a mass called a tumor. A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can grow and spread to other parts of the body. A benign tumor means the tumor can grow but will not spread to distant parts of the body.

In leukemia, a cancer of the blood that starts in the bone marrow, these abnormal cells very rarely form a solid tumor. Instead these cells crowd out other types of cells in the bone marrow. This prevents the production of:

  • Normal red blood cells. Cells that carry oxygen to tissues.

  • White blood cells. Cells that fight infection.

  • Platelets. The part of the blood needed for clotting.

Most of the time, there is no known cause for childhood cancers. Childhood cancers may behave very differently from adult cancers, even when they start in the same part of the body.

Types of childhood cancer

"Childhood cancer" is a general term used to describe a range of cancer types and noncancerous tumors found in children. Childhood cancer may also be called pediatric cancer. Below are the most common types of cancer in children under age 15:

  • Leukemia (accounts for about 29% of childhood cancer cases)

  • Brain and spinal cord tumors (26%), also called central nervous system (CNS) tumors

    • Glial tumors

      • Astrocytoma

      • Oligodendroglioma

      • Ependymoma

      • Choroid plexus carcinoma

      • Oligoastrocytoma

      • Glioblastoma

    • Mixed glial neuronal tumors

      • Ganglioglioma

      • Desmoplastic infantile ganglioglioma

      • Pleomorphioc xanthoastrocytoma

      • Anaplastic ganglioglioma

    • Neural tumors

      • Gangliocytoma

      • Neurocytoma

    • Embryonal tumors

      • Medulloblastoma

      • Medulloepithelioma

    • Ependymoblastoma

      • Atypical Teratoid/Rhabdoid tumor

    • Pineal tumors

      • Pineocytoma

  • Neuroblastoma (6%), a tumor of immature nerve cells. The tumor often starts in the adrenal glands, which are located on top of the kidneys and are part of the body’s endocrine (hormonal) system.

  • Wilms tumor (5%), a type of kidney tumor

  • Non-Hodgkin lymphoma (5%) and Hodgkin lymphoma (3%), cancers that begin in the lymph system

  • Rhabdomyosarcoma (3%), a type of tumor that most commonly begins in the striated skeletal muscles. Non-rhabdomyosarcoma soft tissue sarcomas can also occur in other parts of the body.

  • Retinoblastoma (2%), an eye tumor

  • Osteosarcoma (2%) and Ewing sarcoma (1%), tumors that usually begin in or near the bone

  • Germ cell tumors, rare tumors that begin in the testicles of boys or ovaries of girls. Rarely, these tumors can begin in other places in the body, including the brain.

  • Pleuropulmonary blastoma, a rare kind of lung cancer

  • Hepatoblastoma and hepatocellular carcinoma, types of liver tumors

Cancer in teenagers and young adults

There is an increasing amount of research regarding cancer in children diagnosed after the age of 14. Since these children are starting to enter young adulthood, they may have unique medical, social, and emotional needs that are different from younger children with cancer. They are part of a group often called adolescents and young adults (AYA).

Most often, teenagers and young adults with cancer should be treated at a pediatric oncology center. Ideally, they should be treated at a center where medical oncologists, who are doctors who treat cancer in adults, and pediatric oncologists, who are doctors who treat children with cancer, work together to plan treatment. This will ensure that they receive the newest treatments and are cared for by a team of doctors who are familiar with these diseases.

This is especially important for teenagers who have lymphoma, leukemia, or a bone tumor. Treatment by specialists familiar with these diseases has been shown to improve survival.

Within the AYA group, there are also patients who have types of cancer more commonly found in adults, such as melanoma, testicular cancer, or ovarian cancer. Teenagers with these cancers may receive treatments that are similar to adults, but they also need age-appropriate support for their social and emotional needs. In either the pediatric or adult care centers, age-appropriate information and support is very important for children, teens, and young adults. Talk with your health care team about what support programs are available.

Below are the most common types of cancer in teenagers, ages 15 to 19:

Looking for More of an Introduction?

If you would like more of an introduction, explore these related items. Please note that these links will take you to other sections on Cancer.Net:

  • Cancer.Net Patient Education Videos: View a short video led by an ASCO expert in childhood cancer that provides basic information and areas of research. In addition, the Moving Forward series, in collaboration with The LIVESTRONG Foundation, provides perspectives from both doctors and survivors on topics often faced by young adults living with cancer.

Statistics adapted from the American Cancer Society's publication, Cancer Facts and Figures 2019.

The next section in this guide is Statistics. It helps explain the number of people under age 20 who are diagnosed with childhood cancer and general survival rates. Use the menu to choose a different section to read in this guide.