Regional nodal involvement and patterns of spread along in-transit pathways in children with rhabdomyosarcoma of the extremity: a report from the Children's Oncology Group.
OBJECTIVE
To evaluate the incidence and prognostic factors for regional failure, with attention to the in-transit pathways of spread, in children with nonmetastatic rhabdomyosarcoma of the extremity.


METHODS
The Intergroup rhabdomyosarcoma studies III, IV-Pilot, and IV enrolled 226 children with rhabdomyosarcoma of the extremity. Failure at the in-transit (epitrochlear/brachial and popliteal) and proximal (axillary/infraclavicular and inguinal/femoral) lymph nodes was evaluated. The median follow-up for the surviving patients was 10.4 years.


RESULTS
Of the 226 children, 55 (24%) had clinical or pathologic evidence of either in-transit and/or proximal lymph node involvement at diagnosis. The actuarial 5-year risk of regional failure was 12%. The prognostic factors for poor regional control were female gender and lymph node involvement at diagnosis. In the 116 patients with a distal extremity primary tumor, 5% had in-transit lymph node involvement at diagnosis. The estimated 5-year incidences of in-transit and proximal nodal failure was 12% and 8%, respectively. The in-transit failure rate was 0% for patients who underwent radiotherapy and/or underwent lymph node sampling of the in-transit nodal site but was 15% for those who did not (p = .07). However, the 5-year event-free survival rate did not differ between these two groups (64% vs. 55%, respectively, p = .47).


CONCLUSIONS
The high incidence of regional involvement necessitates aggressive identification and treatment of regional lymph nodes in patients with rhabdomyosarcoma of the extremity. In patients with distal extremity tumors, in-transit failures were as common as failures in more proximal regional sites. Patients who underwent complete lymph node staging with appropriate radiotherapy to the in-transit nodal site, if indicated, were at a slightly lower risk of in-transit failure.
La
Trang H
TH
Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA.
Wolden
Suzanne L
SL
Rodeberg
David A
DA
Hawkins
Douglas S
DS
Brown
Kenneth L
KL
Anderson
James R
JR
Donaldson
Sarah S
SS
D000704:Analysis of Variance; D002648:Child; D018572:Disease-Free Survival; D005121:Extremities; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D010865:Pilot Projects; D011379:Prognosis; D012208:Rhabdomyosarcoma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000556:secondary* / Q000601:surgery; D012737:Sex Factors; D015996:Survival Rate; D017211:Treatment Failure