ABSTRACT
Objective:To investigate the influencing factors of delayed methotrexate (MTX) elimination after high-dose methotrexate (HD-MTX) treatment in children with acute lymphoblastic leukemia (ALL) and the effects of delayed MTX elimination and HD-MTX reduction on the prognosis of children with ALL.Methods:The clinical data of 242 children with ALL diagnosed and treated in Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology from January 2015 to June 2020 in accordance with the Chinese Children's Cancer Group study ALL 2015 (CCCG-ALL 2015) were retrospectively analyzed. Low risk and intermediate/high risk children respectively received 3 g/m 2 and 5 g/m 2 HD-MTX for 4 times, and the serum MTX concentration was monitored. The serum MTX concentration > 1 μmol/L at 44 h of administration was considered as the delayed elimination, which was divided into mild (> 1 μmol/L and ≤ 5 μmol/L), moderate (> 5 μmol/L and ≤ 10 μmol/L) and severe (> 10 μmol/L) delayed elimination. Univariate and multivariate logistic regression analysis were used to analyze the influencing factors of delayed MTX elimination, and univariate Cox proportional hazards model was used to analyze the related factors of ALL relapse. Results:The 242 children with ALL completed 962 times of HD-MTX chemotherapy. The median serum MTX concentration [ M ( Q1, Q3)] at 44 h of administration was 0.45 μmol/L (0.33 μmol/L, 0.72 μmol/L). The total incidence of delayed MTX elimination was 17.7% (170/962). The incidence of mild, moderate and severe delayed elimination was 13.8% (133/962), 2.6% (25/962) and 1.2% (12/962), respectively. Logistic regression analysis showed that age ≥ 7 years old ( OR = 1.68, 95% CI 1.17-2.41, P = 0.005), MTX dose >3 g/m 2 at each course ( OR = 2.14, 95% CI 1.52-3.03, P < 0.001) and the first course of HD-MTX chemotherapy ( OR = 2.05, 95% CI 1.43-2.93, P < 0.001) were independent risk factors for delayed MTX elimination. The median follow-up time was 50 months (34 months, 68 months), 12.8% (31/242) of the children relapsed, and the median relapse time was 30 months (30 months, 39 months). Univariate Cox regression analysis showed that there were no significant differences in the relapse rates among children with different gender, immunophenotype, risk, the number of delayed MTX elimination, and the completion of HD-MTX chemotherapy (the ratio of MTX average dose to initial planned dose) (all P > 0.05). Conclusions:The independent risk factors of delayed elimination of MTX in children with ALL are age ≥ 7 years old, MTX dose > 3 g/m 2 at each course and the first course of HD-MTX chemotherapy. Delayed elimination of MTX and reduction of HD-MTX have no significant effect on ALL relapse.
ABSTRACT
BACKGROUND: High doses of methotrexate (MTX) are often used in various chemotherapy protocols to treat acute lymphoblastic leukemia (ALL) and non-Hodgkin's lymphoma (NHL) in children, but its delayed elimination increases the occurrence of adverse events, such as bone marrow suppression. The aim of this study was to investigate the elimination of MTX at 24 and 48 hours. METHODS: We retrospectively analyzed electronic medical records of ALL or NHL pediatric patients who received 5 g/m² MTX infusion over 24 hours (between June, 2012 and July, 2018) at the Yonsei University Health System, Korea. The delayed elimination of MTX concentrations was assessed with 100 or 150 µM MTX at 24 hours, and 2 or 5 µM at 48 hours. RESULTS: Among the 85 MTX cycles administered, 23 cycles were classified in delayed elimination group, and 62 cycles showed normal elimination. At 24 hours, the delayed elimination group with MTX concentration > 100 µM showed higher percentage than group with MTX concentration < 100 µM (45.8% vs. 19.7%, p = 0.015). However, no differences were observed at 150 µM MTX (p = 0.66). At 48 hours, the delayed elimination was higher than the normal elimination at both concentration baselines (p < 0.001 at 2 µM, p = 0.024 at 5 µM). CONCLUSIONS: MTX concentrations greater than 100 µM show high probability of delayed elimination at 24 hours. When MTX levels are above normal, leucovorin and hydration regimens should be continued to prevent delayed elimination.