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.
Zhuge
Ying
Y
Division of Pediatric Surgery, DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.
Cheung
Michael C
MC
Yang
Relin
R
Perez
Eduardo A
EA
Koniaris
Leonidas G
LG
Sola
Juan E
JE
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*