Background: We conducted a retrospective analysis to investigate the clinical
outcome of combined modality therapy using multiagent chemotherapy, nephrectomy,
and radiotherapy in treatment of children with Wilms' tumor.
Methods: This study was conducted on 91 cases of newly diagnosed Wilms' tumor
from January 2001 until February 2012. Patients were categorized into two groups
according to treatment approach: i) preoperative chemotherapy with delayed surgery
(group A; n=66) and ii) immediate surgery (group B; n=25).
Results: Preoperative chemotherapy showed a 54.5% partial response rate in
group A patients. A final stage distribution indicated that the majority of patients
(64%) from both groups were considered to be in the early disease stages (I and II).
The median follow up was 49 months (range 3-124). The five-year overall survival rate
was 66.5%, whereas the event-free survival rate was 62.5%. In univariate analysis, factors
associated with statistically significant reduction in overall (P<0.0001) and event-free
survival (P=0.0001) rates included advanced disease stages (P<0.0001 for both) and
blastimal subtype (P=0.0067 for overall survival; P=0.012 for event-free survival). Age
of >24 months was associated with a significant reduction in the overall survival rate
(P=0.038, HR: 0.438, 95% CI: 0.192-0.953), but was not significant in terms of eventfree
survival (P=0.104, HR: 0.539, 95% CI: 0.256-1.136). Age >24 months (P=0.0095),
disease stage (P=0.0014), and blastimal subtype (P=0.006) were associated with
significant increases in relapse rate.
Conclusion: Preoperative chemotherapy resulted in a final stage redistribution that
placed the majority of patients in the early stages of the disease. Age at diagnosis, disease
stage, and histological subtype significantly affected survival and relapse rates.