Background: Intensified chemotherapy may improve the outcome of patients with high-risk pediatric sarcomas. Vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide are highly effective against pediatric sarcomas. The authors investigated the feasibility of administering these agents concomitantly within a defined period.

Methods: In the prospective high-risk sarcoma (HIRISA) Phase II trial HIRISA1, pediatric patients with high-risk sarcomas received 3 cycles of intensive vincristine, ifosfamide, etoposide, cyclophosphamide, and doxorubicin (VACIE) before radiotherapy and/or surgery began at Week 9 with concurrent vincristine, cyclophosphamide, and doxorubicin (Week 9) and vincristine and ifosfamide (Week 12). Three additional cycles of VACIE were then given. After delayed hematologic recovery in the first 11 patients, the protocol was modified (HIRISA2) to delay local control therapy until after 5 cycles of VACIE (to be completed within 18 weeks). Patients who responded to the protocols were eligible for myeloablative consolidation with autologous stem cell support.

Results: Eleven of 24 patients (median age, 14.9 years) had Ewing sarcoma family of tumors, 9 patients had rhabdomyosarcoma, and 4 patients had unresectable desmoplastic small round cell tumors. Seven of 13 patients on HIRISA2, but none of 11 patients on HIRISA1, completed therapy within the specified time. Reversible Grade 4 myelosuppression was the most common toxicity. Major nonhematologic toxic effects were mucositis, nutritional impairment, hypotension, and peripheral neuropathy. Three patients died of toxicity. The 5-year survival and 5-year event-free survival estimates both were 45.8% +/- 11.2%.

Conclusions: The feasibility of administering intensive chemotherapy regimens like VACIE was dependent in part on the timing of local control therapy. This regimen was associated with significant toxicity.