Purpose of review: The management of Wilms' tumor continues to evolve with two different approaches being taken by the National Wilms Tumor Study in North America and the International Society of Pediatric Oncology in Europe in regards to preoperative chemotherapy. Limiting the duration, dosage, and number of chemotherapeutic agents and the dosage of radiotherapy are common goals in both trials.
Recent findings: Contralateral exploration of unilateral tumors will no longer be recommended in future National Wilms Tumor Studies. Percutaneous biopsy for tissue diagnosis is quite accurate, but there are concerning complications with its use. Partial nephrectomy is successful for low risk unilateral Wilms tumor, but its indications remain controversial. The surgical complication rate was similar between the National Wilms Tumor Study and the International Society of Pediatric Oncology, but intraoperative tumor spill was higher in the North American trials. Doxorubicin decreased the risk of recurrence in stage III tumors by 50%, and its current dose is not associated with late congestive heart failure. For selected patients, shorter courses of vincristine/dactinomycin or vincristine alone show equivalent results compared to current regimens. A longer course of chemotherapy (including doxorubicin) for clear cell sarcoma improves recurrence-free survival. Patients with Wilms' tumor, aniridia, major genitourinary malformations, and mental retardation, the WAGR syndrome, have a 50% chance of unexplained end-stage renal disease 20 years after treatment.
Summary: Less aggressive means of diagnosis and treatment for Wilms' tumor are continuing to achieve very good cure rates while lowering long term morbidity for low risk patients. High-risk patients with unfavorable histology or the WAGR syndrome benefit from more intensive treatment and long-term follow-up.