Wilms' tumor: past, present and (possibly) future.

Wilms' tumor is one of the successes of pediatric oncology, with an overall cure rate of over 85%, using relatively simple therapies. This excellent outcome has been the result of collaborative efforts among surgeons, pediatricians, pathologists and radiation oncologists. The results that have been achieved in children with Wilms' tumors support the strong value of the multidisciplinary team approach to cancer. The two largest cooperative groups that have studied the optimum treatment for Wilms' tumor are the National Wilms' Tumor Study group in North America and the International Society of Pediatric Oncology, involving European and other countries. The National Wilms' Tumor Study group recommends primary surgery before any adjuvant treatment, whereas the International Society of Pediatric Oncology trials are based on the use of preoperative chemotherapy. The debate on primary chemotherapy versus primary nephrectomy appears to have been overcome, in the sense that the advantages and disadvantages of these two diverse methods have emerged from large and well-performed clinical trials, and comparably low doses of anthracyclines and radiotherapy are now used. Challenges remain in identifying novel molecular, histological and clinical risk factors for stratification of treatment intensity. This could allow a safe reduction in therapy for patients known to have an excellent chance of cure with the current therapy, while identifying, at diagnosis, the minority of children at risk of relapse, who will necessitate more aggressive treatments. Another positive factor is the substantial progress that has been made in the cure for recurrent patients, with long-term survivals shifting from 30 to almost 60% in more recently treated patients with intensive-dose chemotherapy regimens. The combination of lower relapses and higher salvage rates translated into significantly improved overall survival for Wilms' tumor patients as a whole. This review covers current concepts on treatment strategies for Wilms' tumor, with an overview of the results and achievements of the important clinical trials.