[Toxicity of high dose methotrexate repeated infusions in children treated for acute lymphoblastic leukemia and...

We evaluated and compared hematologic, hepatic and renal cumulative toxicity of high dose methotrexate (HDMTX) repeated courses in two groups of pediatric patients: 22 patients affected by "non B" acute lymphoblastic leukemia (ALL) treated, in consolidation phase, with four courses of HDMTX 5 g/mq given intravenously over 24 hours infusion (for a total of 88 courses) according to the Italian Cooperative Protocols AIEOP LLA-88; 18 patients affected by non metastatic osteosarcoma of extremities (OST) treated, in preoperative and postoperative phases, with five courses of HDMTX 8 g/mq given intravenously over 6 hours infusion (for a total of 90 courses) according to CNR-NEO 2 protocol. Severe myelosuppression (neutropenia < 500/microliters and/or thrombocytopenia < 25000/microliters) was more frequently observed in ALL (7% of infusions) than in OST (3%). Hepatotoxicity (serum transaminase elevation > 350 IU/l) was significantly more frequent (p < 0.001) in OST (32% of courses) than ALL (6%). Nephrotoxicity was assimilable in the two groups and the elevation of serum creatinine was never higher than 1.9 mg/dl. We did not observe any increase of hematologic, hepatic and renal toxicity following the HDMTX courses repetition.