Shorter-duration therapy using vincristine, dactinomycin, and lower-dose cyclophosphamide with or without radiotherapy for patients with newly diagnosed low-risk rhabdomyosarcoma: a report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group.

ABSTRACT: Intergroup Rhabdomyosarcoma Study Group (IRSG) studies III and IV showed improved failure-free survival (FFS) rates with vincristine, dactinomycin, and cyclophosphamide (VAC; total cumulative cyclophosphamide dose, 26.4 g/m(2)) compared with vincristine and dactinomycin (VA) for patients with subset-one low-risk embryonal rhabdomyosarcoma (ERMS; stage 1/2 group I/II ERMS or stage 1 group III orbit ERMS). The objective of Children's Oncology Group ARST0331 was to reduce the length of therapy without compromising FFS for this subset of low-risk patients by using VA in combination with lower-dose cyclophosphamide (total cumulative dose, 4.8 g/m(2)) plus radiotherapy (RT).This noninferiority prospective clinical trial enrolled newly diagnosed patients with subset-one clinical features. Therapy included four cycles of VAC followed by four cycles of VA over 22 weeks. Patients with microscopic or gross residual disease at study entry received RT.With a median follow-up of 4.3 years, we observed 35 failures among 271 eligible patients versus 48.4 expected failures, calculated using a fixed outcome based on the FFS expected for similar patients treated on the IRSG D9602 protocol. The estimated 3-year FFS rate was 89% (95% CI, 85% to 92%), and the overall survival rate was 98% (95% CI, 95% to 99%). Patients with paratesticular tumors had the most favorable outcome. Three-year cumulative incidence rates for any local, regional, or distant failures were 7.6%, 1.5%, and 3.4%, respectively.Shorter-duration therapy that included lower-dose cyclophosphamide and RT did not compromise FFS for patients with subset-one low-risk ERMS.

SUBMITTER: Walterhouse DO 

PROVIDER: S-EPMC4209105 | biostudies-other | 2014 Nov

REPOSITORIES: biostudies-other