In Canada this year, cancer affected about 15 out of 100,000 girls and 17 out of 100,000 boys under the age of 19.

Among all age groups, the most common childhood cancers are leukemia, lymphoma, and brain cancer. As children enter their teen years, there is also an increase in the incidence of osteosarcoma (bone cancer). The sites of cancer are different for each type, as are treatment and cure rates.

Leukemia

Leukemias are the most common childhood cancers. They account for about one third of all childhood cancers. Acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML) are the most common types of leukemia in children. Leukemia may be cause bone and joint pain, weakness, bleeding, fever, weight loss, and other symptoms.

Brain and nervous system cancers

Brain and other nervous system cancers are the second most common cancers in children, making up about 21% of childhood cancers. Most brain cancers of children involve the cerebellum or brain stem. In early stages they can cause headaches, nausea, vomiting, blurred or double vision, dizziness, and trouble walking or handling objects. Adults are more likely to develop cancers in different parts of the brain--usually the cerebral hemispheres. Spinal cord tumors are less common than brain tumors in both children and adults.

Neuroblastoma

Neuroblastoma is a form of cancer that starts in certain types of nerve cells found in a developing embryo or fetus. This type of cancer occurs in infants and young children. It is most often found during the first year of life. It is rarely found in children older than 10. This tumor can start anywhere but usually occurs in the belly (abdomen) and is noticed as swelling. It can also cause bone pain and fever. It accounts for about 7% of childhood cancers.

Wilms tumor

Wilms tumor is a cancer that starts in one, or rarely, both kidneys. It is most often found in children about 3 years old, and is uncommon in children older than age 6. It can show up as a swelling or lump in the belly (abdomen). Sometimes the child may have other symptoms, such as fever, pain, or poor appetite. Wilms tumor accounts for about 5% of childhood cancers.

Lymphoma

Non-Hodgkin lymphoma and Hodgkin lymphoma (sometimes called Hodgkin disease, Hodgkin's disease, or Hodgkin's lymphoma), are cancers that start in lymph tissues, such as the tonsils, lymph nodes, and thymus. These cancers may spread to bone marrow and other organs, which can cause different symptoms depending on where it is growing. They also can cause fever, sweats, weakness, and swollen lymph nodes in the neck, armpit, or groin.

Hodgkin lymphoma can occur in both children and adults, and accounts for about 4% of childhood cancers. It is more common, though, in 2 age groups: early adulthood (age 15 to 40, usually people in their 20s) and late adulthood (after age 55). Hodgkin lymphoma is rare in children younger than 5 years of age. About 10% to 15% of cases are diagnosed in children and teenagers.

Non-Hodgkin lymphoma makes up a little more than 4% of childhood cancers, and can cause symptoms much like those of Hodgkin lymphoma. It can also cause other symptoms depending on where it starts in the body.

Rhabdomyosarcoma

Rhabdomyosarcoma is the most common soft tissue sarcoma in children. It makes up a little more than 3% of childhood cancers. This tumor starts in the same embryonic cells that develop into striated (voluntary) muscles. It can happen in the head and neck, groin, abdomen, pelvis, arms and legs. It may cause pain, swelling (a lump), or both.

Retinoblastoma

Retinoblastoma is a cancer of the eye. It is rare, accounting for just under 3% of childhood cancers. It usually occurs in children under the age of 4, and is seldom found in children older than 6.

Bone cancers

Primary bone cancers (cancers that start in the bones) occur most often in children and adolescents. Primary bone cancer is different from metastatic bone cancer, which is cancer that has spread from another site to the bone. Metastatic bone cancer is named for the place the cancer came from. For instance, it might be described as prostate cancer that has spread (metastasized) to the bone, or prostate cancer with bone metastasis.

Metastatic bone cancer is more common than primary bone cancer because many types of cancer can spread to the bone. Two types of primary bone cancers occur in children:

Osteosarcoma is uncommon, accounting for almost 3% of all new childhood cancer cases in the United States. It often causes no pain or symptoms until swelling starts, but sometimes there is bone pain that keeps getting worse. For more information see our document Osteosarcoma.

Ewing sarcoma is a less common primary bone cancer which can cause bone pain. It is mostly found in adolescents. It accounts for a little more than 1% of childhood cancers.