Comparison of self-report and electronic monitoring of 6MP intake in childhood ALL: a Children's Oncology Group study.
Adequate exposure to oral 6-mercaptopurine (6MP) during maintenance therapy for childhood acute lymphoblastic leukemia (ALL) is critical for sustaining durable remissions; accuracy of self-reported 6MP intake is unknown. We aimed to directly compare self-report to electronic monitoring (Medication Event Monitoring System [MEMS]) and identify predictors of overreporting in a cohort of 416 children with ALL in first remission over 4 study months (1344 patient-months for the cohort) during maintenance therapy. Patients were classified as "perfect reporters" (self-report agreed with MEMS), "overreporters" (self-report was higher than MEMS by ≥5 days/month for ≥50% of study months), and "others" (not meeting criteria for perfect reporter or overreporter). Multivariable logistic regression examined sociodemographic and clinical characteristics, 6MP dose intensity,TPMTgenotype, thioguanine nucleotide levels, and 6MP nonadherence (MEMS-based adherence <95%) associated with the overreporter phenotype; generalized estimating equations compared 6MP intake by self-report and MEMS. Self-reported 6MP intake exceeded MEMS at least some of the time in 84% of patients. Fifty patients (12%) were classified as perfect reporters, 98 (23.6%) as overreporters, 2 (0.5%) as underreporters, and 266 (63.9%) as others. In multivariable analysis, the following variables were associated with the overreporter phenotype: non-white race: Hispanic, odds ratio (OR), 2.4,P= .02; Asian, OR, 3.1,P= .02; African American,P< .001; paternal education less than college (OR, 1.4,P= .05); and 6MP nonadherence (OR, 9.4,P< .001). Self-report of 6MP intake in childhood ALL overestimates true intake, particularly in nonadherent patients, and should be used with caution.
Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL.
Wendy
W
Landier
Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL.
Yanjun
Y
Chen
Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL.
Lindsey
L
Hageman
Department of Population Sciences, City of Hope, Duarte, CA.
Heeyoung
H
Kim
Department of Hematology/Oncology, Children's Hospitals and Clinics of Minnesota, Minneapolis, MN.
Bruce C
BC
Bostrom
Department of Pediatrics, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, CA.
Jacqueline N
JN
Casillas
Division of Pediatric Hematology/Oncology, Helen DeVos Children's Hospital at Spectrum Health/Spectrum Health at Butterworth Campus, Grand Rapids, MI.
David S
DS
Dickens
Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN.
William E
WE
Evans
Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO.
Kelly W
KW
Maloney
Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, CA.
Leo
L
Mascarenhas
Department of Pediatrics, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, Pittsburgh, PA; and.
A Kim
AK
Ritchey
Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, CA.
Amanda M
AM
Termuhlen
Department of Pediatrics, Perlmutter Cancer Center, New York University-Langone Medical Center, New York, NY.
William L
WL
Carroll
Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN.
Mary V
MV
Relling
Department of Population Sciences, City of Hope, Duarte, CA.
F Lennie
FL
Wong
Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL.
Smita
S
Bhatia
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D060046:Maintenance Chemotherapy; D008297:Male; D015122:Mercaptopurine / Q000008:administration & dosage* / Q000493:pharmacokinetics; D008991:Monitoring, Physiologic; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000097:blood* / Q000188:drug therapy*; D057566:Self Report
D015122:Mercaptopurine