Updated Statistics on Child and Adolescent Brain Tumors

Study finds that the diagnosis of brain tumors among children and adolescents has slightly increased.

When brain tumors rapidly grow into nearby tissue, they are considered cancerous (malignant). A little less than a third of brain tumors in children and about half of those in teens are noncancerous (nonmalignant, also called benign/borderline). Noncancerous tumors are contained within the original layer of brain or CNS tissue. This means they don’t spread to other places in the body, but they may still grow in size. As a result, even noncancerous tumors can cause substantial harm because, depending on their size and location, they can cause irreversible damage to the developing young brain.

The incidence rate (number of tumors diagnosed per 100,000 children) for cancerous brain tumors has increased very slowly over time, and a new collaborative study from the Central Brain Tumor Registry of the US and the American Cancer Society (ACS) showed that this trend continued during the most recent decade of available data.

The Research

The study, led by Kim D. Miller, MPH, an ACS epidemiologist in the Surveillance and Health Equity Science department, found a 0.7% yearly increase from 2008 to 2017 in incidence rates of cancerous brain tumors among children and a 0.5% yearly increase among adolescents.

Here are some other key findings from the study about childhood and adolescent brain tumors.

Incidence and Mortality Rates

• Incidence rates for cancerous brain tumors in children are generally similar by sex, unlike rates in adults, where the incidence rate is 30% higher for males.
• Incidence rates of cancerous brain tumors are highest in White children, which is similar to adult cancerous brain tumors. However, death rates in White and Black children are similar, reflecting large survival disparities for Black children (see survival rates below).
• The types of brain tumors that are common in childhood differ from those in adults. For example, pilocytic astrocytomas, embryonal tumors (such as medulloblastoma), and germ cell tumors all account for a higher proportion of brain tumor cases in children than in adults.
• Incidence rates for cancerous tumors peak in children ages 1 to 4 years and decline thereafter, with variation by subtype. For example, rates for atypical teratoid/rhabdoid tumors are highest in infants, whereas medulloblastoma occurs most commonly between the ages of 1 and 10.
• Incidence rates for noncancerous tumors decrease immediately after infancy, but the rates subsequently continue to rise into adolescence, following the pattern of pituitary adenomas and germ cell tumors.
  

Survival Rates

• 5-year survival rates for children and adolescents with cancerous brain tumors vary greatly by subtype.
• 5-year survival rates are lowest (70%) in Black children and adolescents with brain cancer and highest (79%) in White patients. The racial disparity among children likely reflects less access to appropriate treatment and enrollment in clinical trials among non-White patients.
  

Late Effects

Compared with their cancer-free siblings, adult survivors of childhood brain and other CNS tumors have a/an:

• Elevated risk for endocrine disorders, including hypothyroidism, as well as cardiovascular problems such as blood clots.
• Lower level of education, higher level of unemployment, lower income, and are less likely to be married.
• Higher prevalence of depression. Non-White survivors experience higher levels of distress than White survivors.
  

Why It Matters

The study authors emphasized that because of the aggressive nature of many cancerous subtypes and limited knowledge about their cause (etiology), ongoing updates of the descriptive epidemiology of these tumors is essential. That requires cancer registries to have more resources to collect and report data in a way that is timely, specific, and broadly consistent across the US.

That enhanced information can allow for ongoing research about the causes of sex, age, and racial/ethnic differences in occurrence, especially for rarer subtypes and understudied populations—and to continue to explore racial/ethnic disparities in the access and receipt of treatment.