Outcomes of Children With Favorable Histology Wilms Tumor and Peritoneal Implants Treated in National Wilms Tumor Studies-4 and -5

Abstract

There are no published reports on the optimal management and survival rates of children with Wilms tumor (WT) and peritoneal implants (PIs). Among favorable histology WT patients enrolled in the National Wilms Tumor Study (NWTS)-4 and NWTS-5, 57 children had PIs at the time of nephrectomy. The median age was 3 years 5 months (range, 3 months to 14 years). The majority of children (42 of 57 [74%)] had Stage III tumors; 15 had Stage IV disease. All patients received multimodality therapy. Of 56 children who underwent primary surgery, 48 (84%) had gross total resection of all tumors. All patients received 3-drug chemotherapy with vincristine, dactinomycin, and doxorubicin. Whole-abdomen radiotherapy (RT) was used in 47 patients (82%), and in 50 patients (88%) the RT dose was 10.5 Gy. After a median follow-up of 7.5 years, the overall abdominal and systemic tumor control rates were 97% and 93%, respectively. A comparative analysis between children with PIs and those without PIs showed no significant differences in the clinical characteristics between the two groups. The 5-year event-free survival rates with and without PIs were 90% (95% confidence interval, 78-96%) and 83% (95% confidence interval, 81-85%) respectively (p = 0.20). Multimodality therapy with surgery, whole-abdomen RT, and three-drug chemotherapy delivered according to the NWTS-4 and -5 protocols resulted in excellent abdominal and systemic tumor control rates. All children should be monitored in long-term surveillance programs for the early detection and management of therapy-related toxicities.