The 2026 Childhood Cancer Report
From diagnosis to research: measuring momentum in the search for cures
Glossary of Terms
Age-Adjusted
A way of comparing data between different populations by taking into account differences in age distribution. This makes it easier to see true trends, not just the effects of having more younger or older people in one group.
Cancer Registry
A database that collects and stores information about cancer cases, such as diagnosis, type, treatment, and outcomes. Cancer registries help researchers and public health experts track trends and improve care. In the United States, each state office of public health has a cancer registry which reports data to the national registry. Not every country has a robust or comprehensive system of cancer registries.
Case Count
The actual number of children diagnosed with cancer in a certain group or area during a specific period.
Childhood Cancer
Cancers that are diagnosed in children, adolescents, and young adults under the age of 19. These cancers often differ from those seen in adults—they tend to start in developing cells and tissues and are not usually linked to lifestyle or environmental factors.
Incidence Rate
The number of new cases of a disease, such as cancer, diagnosed in a specific group of people during a certain time period—usually expressed as the number of cases per 100,000 children each year.
Malignancy
A term for cancerous tumors or diseases that can grow uncontrollably and spread to other parts of the body.
Mortality Rate
The number of deaths from a disease in a specific group of people during a certain time—usually shown as the number of deaths per 100,000 children each year.
Overall Survival Rate
The percentage of people who are still alive after a certain amount of time (often 5 years) after being diagnosed with cancer, no matter the cause of death.
Population-Based
Data or studies that include all people in a defined population (such as all children in the United States).
Prevalence
The total number of people who are living with cancer or who have ever been diagnosed with it at a given time. Depending on context, this may refer to current prevalence (people currently living with cancer) or lifetime prevalence (all people ever diagnosed, regardless of current status).
Primary Site
The part of the body where the cancer first started to grow, before it spread elsewhere.
Progression-Free Survival
The length of time during and after treatment that the cancer does not get worse. It is often used in studies to see how well a new treatment stops the disease from progressing.
Refractory
Describes cancer that does not respond to treatment or stops responding after an initial response. A refractory cancer keeps growing or does not go away despite therapy.
Relative Survival Rate
A measure that compares how long people with cancer live, on average, after diagnosis compared to people of the same age and sex who do not have cancer. It helps show how well treatments are improving survival. This can also be represented on a specific disease basis.
SEER (Surveillance, Epidemiology, and End Results Program)
A long-running program of the U.S. National Cancer Institute that collects detailed information on cancer cases across many regions of the country. SEER data are used to track trends in cancer incidence, survival, and mortality.
Standard of Care
The best-known and most widely accepted treatment for a disease, based on evidence and expert consensus. It represents what doctors generally agree is the most effective and safest option.