Pediatric non-Wilms renal tumors: subtypes, survival, and prognostic indicators.
BACKGROUND
To determine the outcomes and predictors of survival for pediatric non-Wilms renal tumors (NWRT).


METHODS
The SEER database (1973-2005) was queried for all patients < 20 y of age.


RESULTS
Overall, 349 cases of NWRT were identified. The major histologic groups included renal cell carcinoma (RCC) (44%), clear cell sarcoma of the kidney (CCSK) (17%), and malignant rhabdoid tumor (MRT) (12%). A bimodal age distribution was observed, with tumors commonly presenting in patients ≤4 y of age and ≥15 y of age. More than 50% of RCC presented at ≥15 y of age, whereas ≥80% of CCSK or MRT patients were ≤4 y of age. Most RCC (57%) and CCSK (53%) were locally staged while most MRT presented with distant disease (51%, P < 0.001). Overall 10-y survival was 63% with improved survival observed in patients with CCSK (79%) and RCC (70%) versus MRT (29%, P < 0.001). By univariate analysis, surgical resection was associated with improved overall 10-y survival (68% versus 30%, P < 0.001), while no benefit was observed for radiotherapy (60% versus 63%, P = 0.8). By multivariate analysis, worse overall survival was observed for patients ≥ 10 y old (HR 4.01, P = 0.013) and those with advanced disease (HR = 12.78, P < 0.001). Patients with MRT (HR = 11.61, P < 0.001) and CCSK (HR = 3.68, P = 0.038) had significantly worse prognosis compared with those with RCC. Surgical resection improved overall survival (HR = 0.36, P = 0.001).


CONCLUSIONS
For pediatric NWRT, younger patients and those with RCC have improved survival, while a diagnosis of MRT portends a worse prognosis. Surgical extirpation significantly improves survival for all patients.
Division of Pediatric Surgery, DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.
Ying
Y
Zhuge
Michael C
MC
Cheung
Relin
R
Yang
Eduardo A
EA
Perez
Leonidas G
LG
Koniaris
Juan E
JE
Sola
D000293:Adolescent; D000328:Adult; D002292:Carcinoma, Renal Cell / Q000401:mortality*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007680:Kidney Neoplasms / Q000401:mortality* / Q000473:pathology; D008297:Male; D015999:Multivariate Analysis; D011379:Prognosis; D018335:Rhabdoid Tumor / Q000401:mortality*; D018426:SEER Program; D018227:Sarcoma, Clear Cell / Q000401:mortality*