Cyclophosphamide and Topotecan in Relapsed and Refractory Pediatric Extracranial Solid Tumors: A Retrospective Analysis.

OBJECTIVE

To assess the effectiveness and safety of cyclophosphamide and topotecan in children with relapsed or refractory extracranial solid tumors.

METHODS

This study included children with relapsed or refractory extracranial solid tumors treated with cyclophosphamide (250 mg/m2/day) and topotecan (0.75 mg/m2/day) for 5 days, 3-weekly, between January 2012 and February 2024. Event-free-survival (EFS) and overall survival (OS) were estimated using the Kaplan-Meier method.

RESULTS

Eighteen patients with median (range) age 6 (2-13) years (72% boys) with diagnoses of neuroblastoma (61%), Ewing sarcoma (22%), and rhabdomyosarcoma (17%), were analysed. Median of 4-cycles of chemotherapy was given, mostly as second-line (78%). Among 15 evaluable patients, responses were complete-response (CR, n = 1), partial response (PR, n = 3), stable disease (SD, n = 2), and progressive disease (n = 9); disease control rate (CR + PR + SD) 40%. The median EFS and OS were 3.65 months and 9.72 months, respectively, with 1-year EFS and OS rates of 33% and 45%. There was no treatment-related mortality.

CONCLUSION

Cyclophosphamide-topotecan shows efficacy and acceptable safety in pediatric relapsed/refractory solid cancers, highlighting the need for better strategies to improve outcomes.