Does the time-point of relapse influence outcome in pediatric rhabdomyosarcomas?
BACKGROUND
Childhood rhabdomyosarcoma (RMS), a soft tissue malignant tumor of skeletal muscle origin, accounts for approximately 3.5% of the cases of cancer among children 0-14 years and 2% of the cases among adolescents and young adults 15-19 years of age.


METHODS
We evaluated survival (SUR) after first relapse depending on the time to relapse (TTR) in RMSs of childhood and adolescence. Early, intermediate, and late relapsing patients were evaluated for prognostic risk factors.


RESULTS
Two hundred thirty-four patients with RMS enrolled in the German sarcoma trial CWS-81, CWS-86, CWS-91, and CWS-96 met selection criteria. Of the 234 patients, 35%, 32%, and 33% relapsed within 6 (early), 6-12 (intermediate), and more than 12 (late) months respectively after the end of primary therapy. Four-year SUR was 12%, 21%, and 41% for early, intermediate, and late relapse respectively (P < 0.001). Four-year SUR after local relapse was 18% (early), 38% (intermediate), and 49% (late). Embryonal RMS showed four year SUR of 16%, 30%, and 46% (P < 0.001) whereas alveolar histology showed four year SUR of 8%, 6%, and 23% (P < 0.01) for early, intermediate, and late relapse respectively.


CONCLUSIONS
TTR has significant influence on prognosis in relapsed RMS. It influences SUR independent of other features such as type of relapse, histology, tumor site, primary treatment time or irradiation in primary treatment.
Mattke
Adrian C
AC
Royal Children's Hospital, Department for Paediatric Intensive Care Medicine, Herston, QLD, Australia. adrian.mattke@gmail.com
Bailey
Emily J
EJ
Schuck
Andreas
A
Dantonello
Tobias
T
Leuschner
Ivo
I
Klingebiel
Thomas
T
Treuner
Joern
J
Koscielniak
Ewa
E
D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000401:mortality*; D009367:Neoplasm Staging; D009379:Neoplasms, Muscle Tissue / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology; D011379:Prognosis; D011879:Radiotherapy Dosage; D012208:Rhabdomyosarcoma / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult