Myelotoxicity after high-dose methotrexate in childhood acute leukemia is influenced by 6-mercaptopurine dosing but not by intermediate thiopurine methyltransferase activity.
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Jonsson, Olafur G
Bechensteen, Anne Grete
Frandsen, Thomas L
Weinshilboum, Richard M
MetadataShow full item record
CitationCancer Chemother. Pharmacol. 2015, 75 (1):59-66
AbstractThrough enhancement of 6-mercaptopurine (6MP) bioavailability and inhibition of purine de novo synthesis, high-dose methotrexate (HD-MTX) may increase incorporation into DNA of 6-thioguanine nucleotides, the cytotoxic metabolites of 6MP. Patients with intermediate activity of thiopurine methyltransferase (TPMT(IA)) have higher cytosol 6-thioguanine nucleotide levels. We investigated toxicity following HD-MTX during MTX/6MP maintenance therapy in relation to 6MP and TPMT.
Using linear mixed models, we explored myelo- and hepatotoxicity in relation to 6MP dosage and TPMT phenotype following 1,749 HD-MTX courses to 411 children with acute lymphoblastic leukemia on maintenance therapy.
The degree of myelosuppression following HD-MTX was similar for patients with TPMT(IA) and patients with high TPMT activity (TPMT(HA)), when HD-MTX started with same blood counts and 6MP doses. However, since TPMT(IA) had lower blood counts at initiation of HD-MTX compared with TPMT(HA) patients (median WBC 2.8 vs. 3.3 × 10⁹/L, P = 0.01; median ANC 1.4 vs. 1.7 × 10⁹/L, P = 0.02), TPMT(IA) continued to have lower WBC and ANC levels compared with TPMT(HA) during all 28 days after HD-MTX [relative difference 9 % (95 % CI 2-17), P = 0.02 and 21 % (95 % CI 6-39), P = 0.005]. Still, the fractional decrease in WBC and ANC levels after HD-MTX did not differ between TPMT(IA) and TPMT(HA) patients (P = 0.47; P = 0.38). The degree of leukopenia, neutropenia, thrombocytopenia and rise in aminotransferases were all significantly related to 6MP dose (P < 0.001 for all analyses).
For both TPMT(IA) and TPMT(HA) patients, dose of 6MP prior to HD-MTX should be guided by pre-HD-MTX blood counts, but not by TPMT activity.
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RightsArchived with thanks to Cancer chemotherapy and pharmacology
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- Authors: Schmiegelow K, Ifversen M
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- Prognostic importance of 6-mercaptopurine dose intensity in acute lymphoblastic leukemia.
- Authors: Relling MV, Hancock ML, Boyett JM, Pui CH, Evans WE
- Issue date: 1999 May 1
- Methotrexate/6-mercaptopurine maintenance therapy influences the risk of a second malignant neoplasm after childhood acute lymphoblastic leukemia: results from the NOPHO ALL-92 study.
- Authors: Schmiegelow K, Al-Modhwahi I, Andersen MK, Behrendtz M, Forestier E, Hasle H, Heyman M, Kristinsson J, Nersting J, Nygaard R, Svendsen AL, Vettenranta K, Weinshilboum R, Nordic Society for Paediatric Haematology and Oncology.
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