Wilms Tumor

Wilms tumor, or nephroblastoma, is the most frequent primary renal tumor in the pediatric age group, accounting for 5% of all childhood cancers and affecting one in about 10,000 children. Clinical onset tends to occur between ages 1 and 5 years, with 90% of new cases diagnosed before age 7 years. Despite its malignant nature, long term survival rate after treatment is excellent, being greater than 90% for localized disease and 75% for metastatic disease. Most of the dramatic improvements in survival of these children have been achieved by results from randomized clinical studies conducted by the two largest collaborative groups from both sides of the Atlantic, namely the Children’s Oncology Group (COG—formerly the National Wilms Tumor Study [NWTS]) and the Société Internationale d’Oncologie Pédiatrique (SIOP). Surgery still plays a pivotal role in the multimodal treatment strategy of Wilms tumor, which also includes chemotherapy, and, in certain circumstances, radiation therapy according to patient stratification into welldefined risk groups. Future goals will focus on further reduction in frequency and intensity of acute and late toxicity while maintaining current high rate of cure. Additionally, the use of biomarkers for patient risk stratification and the introduction of newer molecular targeted therapies will hopefully improve prognosis and treatment of the high risk patients.