Rapid advances in the understanding of Wilms' tumor (WT) and its management are being made both in the laboratory and the clinic. Molecular genetic research has implicated loss of a tumor suppressor gene on the short arm of chromosome 11 as one of the pathways responsible for the development of the neoplasm. Preconception maternal (hair dyes) and paternal (occupation) exposures to environmental agents have been the subject of epidemiologic studies of possible risk factors. Histopathologic analyses have identified several different and less common tumor types among those previously aggregated under the WT rubric. WT itself has been subdivided into the so-called favorable histology (FH) and anaplastic forms, the prognosis being worse for the latter. Clinical research has standardized management by surgery, chemotherapy, and radiation therapy (RT) and furthered the identification of risk factors. Patients can now be stratified according to tumor type and stage, and the intensity of treatment modulated accordingly; eg, RT at low doses is used in only 25% of National Wilms' Tumor Study (NWTS) patients without distant metastases. Before the NWTS, it had been given to almost all and at higher doses. Chemotherapy, whether given pre- or postoperatively, is based on dactinomycin and vincristine with Adriamycin [( ADR] doxorubicin; Adria Laboratories, Columbus, OH) added for high-risk patients. The currently used NWTS combined modality therapy for WT patients has dramatically improved survival rates; 95% now are alive 2 years after treatment. Remaining questions are the identification of the late effects of the treatments used and the further refinement of therapy to reduce iatrogenic complications to a minimum.
Loss of allelic heterozygosity at a second locus on chromosome 11 in sporadic Wilms' tumor cells.