Comparison of the prognostic value of assessing tumor diameter versus tumor volume at diagnosis or in response to initial chemotherapy in rhabdomyosarcoma.
OBJECTIVE
In this study on a series of 205 patients with rhabdomyosarcoma, we investigated whether the prognostic effect of tumor size, at diagnosis or in terms of tumor response after induction chemotherapy, differed when tumor diameter or tumor volume were considered.


METHODS
Tumor size was assessed radiologically at diagnosis and, for the 108 patients with measurable disease, after three courses of chemotherapy. The analysis was based on multivariable models (linear for association between size and patient/tumor characteristics, Cox for association with survival). The predictive performance of the Cox model (estimated by V measure) was compared for the tumor's diameter and volume.


RESULTS
Initial tumor size was significantly larger in male or older patients and in T2 or alveolar tumors, but was not associated with the achievement of complete surgical resection. Initial tumor size significantly influenced overall survival. The risk of death was comparable for tumors 10 cm in maximum diameter and 194.0 cm(3) in volume. The predictive performance of the Cox model was much the same when the tumor's diameter or volume was considered. Tumor response was a significant predictor of survival, again irrespective of the type of tumor measurement considered.


CONCLUSIONS
In our analysis, initial tumor size and tumor response were significant prognostic factors in rhabdomyosarcoma, regardless of whether tumor diameter or volume was considered. Three-dimensional tumor assessment was of no greater prognostic value than one-dimensional assessment, neither initially nor after induction treatment.
Ferrari
Andrea
A
Pediatric Oncology Unit, Division of Medical Statistics and Biometry, Radiology and Radiotherapy Department, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Istituto Nazionale Tumori, Milan, Italy. andrea.ferrari@istitutotumori.mi.it
Miceli
Rosalba
R
Meazza
Cristina
C
Casanova
Michela
M
Favini
Francesca
F
Morosi
Carlo
C
Trecate
Giovanna
G
Marchianò
Alfonso
A
Luksch
Roberto
R
Cefalo
Graziella
G
Terenziani
Monica
M
Spreafico
Filippo
F
Polastri
Daniela
D
Podda
Marta
M
Catania
Serena
S
Schiavello
Elisabetta
E
Giannatempo
Patrizia
P
Gandola
Lorenza
L
Massimino
Maura
M
Mariani
Luigi
L
D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007558:Italy; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012208:Rhabdomyosarcoma / Q000188:drug therapy / Q000473:pathology*; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods