Treatment outcomes in adults with favorable histologic type Wilms tumor-an update from the National Wilms Tumor Study Group.

PURPOSE: To describe the clinical outcomes in adults with favorable histologic type (FH) Wilms tumor (WT) registered in the National Wilms Tumor Studies (NWTS) 4-5. We also describe the results of patients treated in the "modern era" (1979-2001) with surgical staging, central pathology review and stage-appropriate multimodality treatment.

METHODS AND MATERIALS: Twenty-three adult patients (> or =16 years of age) with FHWT after central pathology review were registered on NWTS 4-5. The tumor stage distribution was Stage I in 5, Stage II in 8, Stage III in 6, and Stage IV in 4 patients. All patients underwent primary nephrectomy followed by multiagent chemotherapy and/or radiotherapy (RT). All patients underwent tumor stage-based chemotherapy that generally followed existing NWTS Group (NWTSG) protocols. To analyze the outcomes of adult patients treated in the "modern era," the data from this report were combined with the data from 22 patients with FHWT previously reported in 1990 by the NWTSG.

RESULTS: The 5-year relapse-free survival, overall survival, and disease-specific survival (DSS) rate was 77.3%, 82.6%, and 95.7%, respectively, for patients registered in the NWTS 4-5 protocols. Three patients (13%) died of chemotherapy-induced hepatic venoocclusive disease. For a total of 45 adults with FHWTs treated in the "modern era," the overall survival rate was 82%. The survival rate for those with Stage I, II, III, and IV disease was 100%, 92%, 70%, and 73%, respectively. Of the 12 Stage I-II patients treated with two drugs and no RT, the survival rate was 100%. The survival rate for Stage III and IV patients treated with three drugs and RT was 63% and 70%, respectively.

CONCLUSION: The results of this report demonstrate that adults with FHWT treated with a multimodality approach similar to NWTSG protocols have good survival. We recommend that all adult patients be treated with stage-appropriate combined modality therapy, and furthermore, be entered in current Children's Oncology Group WT protocols so that coherent data can be gathered for this relatively rare tumor. Finally, all patients should be monitored for signs and symptoms of hepatic venoocclusive disease.