High-Dose methotrexate in pediatric acute lymphoblastic leukemia: Variability across Mexican centers from a national survey

IntroductionHigh-dose methotrexate (HD-MTX) is a cornerstone of pediatric acute lymphoblastic leukemia (ALL) therapy. It's safe administration requires timely pharmacokinetic monitoring and comprehensive supportive care, which are frequently limited in low- and middle-income countries (LMICs). In Mexico, variability in HD-MTX practices may compromise treatment safety and efficacy. This study aimed to characterize national practice patterns and identify context-specific adaptations in the delivery of HD-MTX in resource constrained settings.MethodsA nationwide, cross-sectional electronic survey was conducted between May and November 2023 among pediatric hematologists and oncologists treating patients younger than 18 years with ALL. The questionnaire assessed institutional guidelines, availability of pharmacokinetic monitoring, and supportive care practices, including hydration, urinary alkalinization, and folinic acid rescue. Data were analyzed descriptively.ResultsA total of 111 specialists from 27 Mexican states participated. Only 56% reported having institutional HD-MTX guidelines. While 97% administered HD-MTX to high-risk ALL patients, only 61% used full protocol-recommended doses, and nearly one-third reported dose reductions. Methotrexate plasma level monitoring was only available in 56% of centers. Most centers (86%) administered HD-MTX exclusively in the inpatient setting. Supportive care practices varied substantially across institutions and risk groups. Reported barriers included limited laboratory capacity (61%), lack of standardized protocols (44%), and delays related to bed availability (39%).ConclusionsOptimizing HD-MTX delivery in Mexico requires integrating standardized clinical practices with targeted system-level interventions to ensure timely access to pharmacokinetic monitoring. The development and implementation of context-adapted national guidelines may improve safety, reduce variability in care, and mitigate outcome disparities in children with ALL.