Highest Incidence Age Groups

Childhood cancer is diagnosed more often in infants and adolescents than in the age groups between the two.

Infants

The incidence of childhood cancer peaks in the first year of life. Infant boys and girls are diagnosed at about the same rate, which is notable because it is the only age for which female childhood cancer rates are not lower than male.

Neuroblastoma is the most common type of infant cancer (28%), followed by leukemias (17%) and central nervous system cancers (13%). Germ cell and soft tissue tumors were each about 6%.

White infants have a substantially higher incidence than black infants for most types of cancer. Leukemias account for a substantial proportion of the racial difference, white infants having a 66% higher incidence than black infants.

Infants often have a poorer prognosis than older children. For instance, the 5-year survival rate in 1995 for all children with acute lymphoblastic leukemia was over 70%, but only 33% for infants. However, survival rates vary according to many factors. For instance, over 80% of all children with neuroblastoma during infancy were alive 5 years after diagnosis, but for those diagnosed at age 1 or older, the rate was only 45%.

The rise in annual incidence rates shown on the chart below may be due, in part, to the improvement in our ability to diagnose these cancers. In earlier years, many patients who had some types of childhood cancer would never have been diagnosed, especially those who did not even require treatment to survive (those who had spontaneous regression).

Research involving infant cancers is very important, as it can lead to advances in treating cancers of all ages. For example, the study of retinoblastoma, and later of Wilms tumor, led to the discovery of two important tumor suppressor genes that are related to adult as well as childhood cancers.

Adolescents

The rate of childhood cancer diagnosed in ages 15-19 is similar to that for ages 0-4, and substantially higher than for ages 5-9 and 10-14.

The most common types of cancers in ages 15-19 are:

• Hodgkins disease 16.1%
• Germ cell tumors 15.2%
• Central nervous system tumors 10%
• Non-Hodgkins lymphoma 7.6%
• Thyroid cancer 7.2%
• Malignant melanoma 7%
• Acute lymphoblastic leukemia 6.4%

This article includes data from:

Cancer Incidence and Survival among Children and Adolescents: United States SEER (Surveillance, Epidemiology, and End Results) Program 1975-1995.

Ries LAG, Smith MA, Gurney JG, Linet M, Tamra T, Young JL, Bunin GR (eds). Cancer Incidence and Survival among Children and Adolescents: United States SEER Program 1975-1995, National Cancer Institute, SEER Program. NIH Pub. Nol 99-4649. Bethesda, MD, 1999.