Prognostic factors and clinical outcomes in children and adolescents with metastatic rhabdomyosarcoma--a report from the Intergroup Rhabdomyosarcoma Study IV.
OBJECTIVE
To identify risk factors associated with outcomes in children with metastatic rhabdomyosarcoma (RMS) treated on the fourth Intergroup Rhabdomyosarcoma Study (IRS-IV).


METHODS
Patients with metastatic RMS were treated with one of two regimens that incorporated a window of either ifosfamide and etoposide (IE) with vincristine, dactinomycin, and cyclophosphamide (VAC) or vincristine, melphalan (VM) and VAC. Study end points were failure-free survival (FFS) and overall survival (OS). Clinical factors including age, histology, sites of primary and metastatic disease, and number of sites of metastatic disease were correlated with those end points.


RESULTS
One hundred twenty-seven patients were eligible for analysis. The estimated 3-year OS and FFS for all patients were 39% and 25%, respectively. By univariate analysis, 3-year OS was significantly influenced by histology (47% for embryonal v 34% for all others, P =.026) and increasing number of metastatic sites (P =.028). By multivariate analysis, the presence of two or fewer metastatic sites was the only significant predictor (P =.007 and.006, respectively). The combination of embryonal histology with two or fewer metastatic sites identified a subgroup with 3-year FFS of 40% and OS of 47%.


CONCLUSIONS
Children with group IV RMS treated on the IRS-IV study had improved OS and FFS if they had two or fewer metastatic sites and embryonal histology. This favorable subset of patients has outcomes approaching those observed in selected patients with localized, nonmetastatic disease. Thus, these patients might not be appropriate candidates for regimens that include experimental agents with substantial toxicities or unproven antitumor activity.
Breneman
John C
JC
Children's Hospital Medical Center, Division of Radiation Oncology, Cincinnati, OH 45219-0757, USA. brenemjc@healthall.com
Lyden
Elizabeth
E
Pappo
Alberto S
AS
Link
Michael P
MP
Anderson
James R
JR
Parham
David M
DM
Qualman
Stephen J
SJ
Wharam
Moody D
MD
Donaldson
Sarah S
SS
Maurer
Harold M
HM
Meyer
William H
WH
Baker
K Scott
KS
Paidas
Charles N
CN
Crist
William M
WM
D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011379:Prognosis; D012208:Rhabdomyosarcoma / Q000175:diagnosis / Q000401:mortality* / Q000556:secondary* / Q000628:therapy; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology