Study to Assess Compliance With Long-Term Mercaptopurine Treatment in Young Patients With Acute Lymphoblastic Leukemia in Remission

PRIMARY OBJECTIVES: I. To determine and compare adherence to maintenance mercaptopurine (6-MP) in a cohort of children with acute lymphoblastic leukemia (ALL) from four different ethnic and racial groups (Caucasians, African-Americans, Hispanics, and Asians) receiving maintenance/continuation chemotherapy, using the following assessments: serial red cell 6-MP metabolites (6-thioguanine \[6TGN\] and methyl thioinosine monophosphate \[TIMP\]); frequency of 6-MP dosing using an electronic pill monitoring system (Microelectromechanical Systems \[MEMS\]?); self-report of adherence to 6-MP by questionnaire. II. To determine the impact of adherence to 6-MP (measured using 6TGN, methyl \[Me\]TIMP, MEMS? and self-report data independently) on event-free-survival (EFS) in the entire cohort, after adjusting for known predictors of disease outcome. III. Define a critical level of adherence (measured independently by 6TGN, MeTIMP, MEMS?, self-report) that has a significant impact on EFS for the entire cohort. IV. Describe prevalence of adherence to 6-MP by ethnicity (6TGN, MeTIMP, MEMS?, Self-report). V. Describe behavioral and socio-demographic predictors of adherence using the questionnaire data. VI. Describe the pill-taking practices in this cohort using the MEMS? data. VII. To evaluate the impact of adherence on ethnic/racial difference in EFS. SECONDARY OBJECTIVES: I. To assess the concordance among 6TGN and MeTIMP levels, electronic pill monitoring, and self-reported adherence in the ethnic/racial groups. OUTLINE: Patients receive an electronic pill monitoring system comprising an empty MEMS? medication bottle with TrackCap? child resistant (CR). The mercaptopurine prescription is filled using this system. Beginning on day 1 of the third or later course of maintenance therapy, patients take all doses of mercaptopurine from the MEMS? medication bottle with TrackCap? CR for at least 169 days. The MEMS? TrackCap? CR is mailed to the Coordinating Center at the end of study. Patients also receive methotrexate orally (PO) as indicated by their individual chemotherapy regimen. NOTE: \*Study closed to accrual for Caucasian and Hispanic patients as of 8/14/2009. After completion of study, patients are followed up every 6 months for 5 years and then annually for up to 10 years.