Table 3. Overview of Wilms Tumor Standard Treatment by Stage continued...
Chemotherapy and/or radiation therapy following biopsy or second-look operation is dependent on the response to initial therapy, with more aggressive therapy required for patients with inadequate response to initial therapy observed at the second procedure or in the setting of anaplasia.[3,17,18,19,20,21,22]
Renal transplantation for children with Wilms tumor is usually delayed until 1 to 2 years have passed without evidence of malignancy. Similarly, renal transplantation for children with Denys-Drash syndrome and Wilms tumor, all of whom require bilateral nephrectomy, is generally delayed 1 to 2 years after completion of treatment for the tumor.
Inoperable Wilms tumors
In North America, standard therapy for Wilms tumor is primary nephrectomy and lymph node sampling followed by adjuvant chemotherapy. However, certain clinical presentations of Wilms tumor are referred to as inoperable Wilms tumor and include the following:
- Metachronous bilateral Wilms tumor.
- Wilms tumor in a solitary kidney.
- Extension of tumor thrombus above the level of the hepatic veins.
- Tumor involves contiguous structures whereby the only means of removing the kidney tumor requires removal of the other structures (e.g., spleen, pancreas, colon but excluding the adrenal gland).
- Pulmonary compromise due to extensive pulmonary metastases.
- Retroperitoneal rupture with free fluid contained by Gerota fascia.
Neoadjuvant chemotherapy consisting of vincristine, dactinomycin, and doxorubicin followed by resection and radiation therapy is the usual treatment for inoperable Wilms tumor. In the case of bilateral Wilms tumor or occurrence in a solitary kidney, the purpose of chemotherapy prior to surgery is to reduce the size of the tumor and allow preservation of maximal renal parenchyma at resection. In the case of extensive vena caval infiltration, initial chemotherapy also results in tumor shrinkage and minimizes the complications associated with subsequent resection and avoids the use of cardiopulmonary bypass.
Adults with Wilms tumor
In an analysis of Wilms tumor patients in the Surveillance, Epidemiology and End Results database, adults (n = 152) had a statistically worse OS (69% vs. 88%, P < .001) than pediatric patients (n = 2,190). Adults diagnosed with Wilms tumor were more likely than pediatric patients to be staged as having localized disease, to not receive any lymph node sampling, and to not receive any radiation treatment. The investigators recommended that all adult patients diagnosed with Wilms tumor should undergo lymph node sampling and that there should be close collaboration with pediatric surgeons and oncologists in treatment planning.
Treatment Options Under Clinical Evaluation
The following treatment options are currently under investigation in Children's Oncology Group (COG) clinical trials. Information about ongoing clinical trials is available from the NCI Web site.
- COG-AREN0532 (Vincristine, Dactinomycin, and Doxorubicin With or Without Radiation Therapy or Observation Only in Treating Younger Patients Who Are Undergoing Surgery for Newly Diagnosed Stage I, Stage II, or Stage III Wilms Tumor): In this study, all tumors will be stratified based on central pathology review and molecular analysis (loss of heterozygosity at chromosomes 1p and 16q). Patients with loss of heterozygosity at 1p and 16q will be upstaged to receive treatment with regimen DD-4A (dactinomycin, doxorubicin, and vincristine for 24 weeks). Patients who are younger than 2 years and have Wilms tumors that weigh less than 550 g and who have a negative microscopic evaluation of lymph nodes are eligible for observation only. Other stage I patients will be treated with the standard therapy regimen EE-4A (dactinomycin and vincristine for 18 weeks) postnephrectomy.