Abstract
BACKGROUND/AIM: High-dose methotrexate (HD-MTX) is pivotal chemotherapy in the treatment of patients with osteosarcoma. Blood concentrations of MTX are associated with several side effects, but there are large individual differences in the elimination of MTX. The aim of this study was to explore risk factors for delayed elimination of MTX in children, adolescents and young adults with osteosarcoma. PATIENTS AND METHODS: We conducted a retrospective study on Japanese patients with osteosarcoma who were treated with HD-MTX at Kanazawa University Hospital from April 2006 to March 2015. Risk factors for delayed elimination of methotrexate were identified by multiple logistic regression analysis. RESULTS: A total of 92 cycles of HD-MTX therapy were analyzed. Female and lower creatinine clearance (CCr) were identified as independent risk factors for delayed elimination of MTX. CONCLUSION: Knowing the factors associated with delayed elimination of MTX could lead to safer and optimized chemotherapy for patients with osteosarcoma.