No evidence of a trial effect in newly diagnosed pediatric acute lymphoblastic leukemia.

Objective: To determine whether clinical trial enrollment by itself is associated with improved outcome.

Design: Retrospective cohort study.

Setting: Seattle Children's Hospital from 1997 to 2005.

Participants: Data were drawn from 322 patients with newly diagnosed acute lymphoblastic leukemia. Main Exposure Enrollment in a Children's Oncology Group or Children's Cancer Group clinical trial.

Main Outcome Measures: (1) Demographic variables associated with trial participation. (2) Event-free survival, which was defined as the time from initial diagnosis to either leukemia recurrence or death from any cause.

Results: No outcome advantage was found for participants in a clinical trial compared with nonparticipants. Additionally, there were not demographic factors associated with increased clinical trial participation.

Conclusions: Clinical trial participation does not, by itself, lead to improved outcome for pediatric patients with acute lymphoblastic leukemia in the current era. Discussions about participation in a clinical trial should focus on improvement of future therapy, not the direct benefit of the research participant.