Background: The combination of topoisomerase I and II chemotherapeutic agents has shown promising preclinical synergistic effects in the treatment of high-grade malignant brain tumors such as high-grade gliomas and choroid plexus carcinomas. To confirm the effectiveness of this treatment combination and determine its possible toxicity, we conducted a retrospective review of the charts of children who received the therapy.
Methods: Patients with relapsed malignant brain tumors who were given an individualized treatment of pegylated (PEG)-liposomal doxorubicin and topotecan were included in our study. PEG-liposomal doxorubicin was given intravenously at a dosage of 30-40 mg/m(2) over 4 h once every 4 weeks. Additionally, an intravenous formulation of topotecan was given orally twice daily and was increased on an individual basis from a starting dosage of 0.3 mg/m(2) per application to a total daily dosage of 0.6 mg/m(2).
Results: Eight patients were included. The main toxicity (NCI-CTC) after three cycles of the combination therapy was grade IV hematotoxicity (n = 3); grade III hematotoxicity (n = 2), grade III stomatitis (n = 1), grade III infection (n = 2), grade III diarrhea (n = 1); and grade II dermatitis (n = 1). In four patients, stable disease was achieved for 9, 23, more than 24, and more than 48 weeks, respectively.
Conclusion: The schedule of PEG-liposomal doxorubicin with 30-40 mg/m(2) every 4 weeks in combination with oral topotecan resulted in tumor response, but the toxicity was high. An individualized increasing dose of PEG-liposomal doxorubicin 10-20 mg/m(2) every two weeks is now recommended.