Prognosis in children with Wilms' tumor metastases prior to or following primary treatment: results from the first National Wilms' Tumor Study (NWTS-1).

Survival data from the first National Wilms' Tumor Study were analyzed on 101 patients who relapsed after primary therapy (group I-III) and on 82 patients who presented initially with metastases (group IV). The group I patients had significantly better 3-year survival rates than group II/III patients (64% vs 37%). Histology, relapse site, and time to relapse all showed strong independent effects on survival even in the presence of other variables. The survival curves were significantly better for patients with favorable histology, extraabdominal metastases, and late metastases. The overall survival (longer than 3 years) was 46% of group I-III patients who relapsed and 56% of group IV patients.