A retrospective study of treatment and prophylaxis of ifosfamide-induced hemorrhagic cystitis in pediatric and adolescent and young adult (AYA) patients with solid tumors.

Objective: Ifosfamide (IFO) is considered an essential drug for the treatment of pediatric, adolescent and young adult patients with solid tumors. Hemorrhagic cystitis (HC) is one of the dose-limiting toxicity of IFO. However, there are insufficient evidence for risk factor and supportive care of IFO-induced HC.

Methods: In this retrospective study, patients (<30-year-old) with malignant solid tumors who had been treated with IFO-based chemotherapy, were categorized according to the presence or absence of HC, and were analyzed possible risk factors for IFO-induced HC. In our institution, continuous hydration to increase urine output and intravenous 2-mercaptethane sulfonate (mesna) are used for prophylaxis of IFO-induced HC. Increased hydration and dosage of mesna are administered to patients who develop IFO-induced HC; they also receive 24-h continuous infusion of mesna in subsequent treatment cycles.

Results: Nine treatment regimens were used in the 70 study patients. The range of daily IFO dosage was 1.2-3.0 g/m(2). HC occurred in 14/425 IFO-based chemotherapy cycles (3.3%). The daily IFO dosages (mean ± SD) in patients with or without HC were 2.23 ± 0.58 g/m(2) and 1.85 ± 0.50 g/m(2), respectively (P = 0.006). Only one of the nine patients who developed IFO-induced HC had experienced this complication in a subsequent cycle of treatment.

Conclusion: The incidence of IFO-induced HC may be associated with the dosage of IFO. When administering IFO higher than 2.0 g/m(2)/day, the volume of hydration, dosage of mesna and duration of mesna infusion should be increased to prevent HC.