Participant Demographics

Study size

LTFU study size pie chart

Nearly 25,000 people from the United States and Canada who were treated as children for cancer or a similar illness currently participate in this study. Treatments for childhood cancer have changed over time, in part because of what has been learned from the Long-Term Follow-Up Study.

When the study began in 1994, we enrolled participants who were diagnosed between 1970 and 1986.  More recently we have added a new generation of participants diagnosed between 1987 and 1999.

Sibling comparison group

Number of survivors and their siblings

More than 4,000 of their siblings (brothers and sisters) who did not have a serious illness as a child also participate in the Long-Term Follow-Up Study, serving as a comparison group. The sibling group is similar to the LTFU Study cohort in almost every way except they did not receive treatment for cancer or a similar childhood illness.

The LTFU Study follows the health status of participants and their siblings over time. If survivors in the study have different health outcomes when compared to their brothers and sisters, these results provide strong evidence about how cancer treatments affect long-term health.

Treatment decade

LTFU treatment decade pie chart

The Long-Term Follow-Up Study includes participants who were diagnosed and treated over the span of 30 years. This allows researchers to show how advances in treatment have improved the lives of survivors.

They can also identify areas where more progress is needed to help children diagnosed with cancer in the future.


LTFU gender pie chart

Because men and women may experience some different issues related to their childhood cancer, it is important to have good representation of both males and females.


Age of survivors and their siblings

Marital status

Demographics by marital status

Geographic Location

Geographic Location

Original Diagnosis

Demographic by Diagnosis

Treatment methods for original diagnosis

Demographis by treatment method