Patients with recurrent rhabdoid tumor of the kidney, clear cell sarcoma of the kidney, neuroepithelial tumor of the kidney, and renal cell carcinoma should be considered for treatment on available phase I and phase II clinical trials.
Table 8. Treatment Options for Recurrent Childhood Kidney Tumors
|Standard-risk relapsed Wilms tumor
||Surgery, radiation therapy, and chemotherapy
|High-risk and very high-risk relapsed Wilms tumor
Chemotherapy, surgery, and/or radiation therapy
|Hematopoietic stem cell transplantation
|Recurrent clear cell sarcoma of the kidney
||Chemotherapy, surgery, and/or radiation therapy
Prognosis, Prognostic Factors, and Risk Categories for Recurrent Wilms Tumor
Approximately 15% of patients with favorable-histology (FH) Wilms tumor and 50% of patients with anaplastic Wilms tumor experience recurrence. Historically, the salvage rate for patients with recurrent FH Wilms tumor was 25% to 40%. As a result of modern treatment combinations, the outcome after recurrence has improved up to 60%.[2,3]
A number of potential prognostic features influencing outcome postrecurrence have been analyzed, but it is difficult to separate whether these factors are independent of each other. Also, the following prognostic factors appear to be changing over time as therapy for primary and recurrent Wilms tumor evolves:
- Anaplastic histology.
- Advanced tumor stage.
- Gender: Gender was predictive of outcome, with males faring worse than females.[2,5]
The National Wilms Tumor Study-5 (NWTS-5 [NCT00002611]) showed that time to recurrence and site of recurrence are no longer prognostically significant.[2,5] However, in a Société Internationale d'Oncologie Pédiatrique (SIOP) study, patients who experienced a pulmonary relapse within 12 months of diagnosis had a poorer prognosis (5-year overall survival [OS], 47%) than did patients who experienced a pulmonary relapse 12 months or more after diagnosis (5-year OS, 75%).
On the basis of these results, the following three risk categories have been identified:
Standard risk: Patients with FH Wilms tumor who relapse after therapy with only vincristine and/or dactinomycin. These patients are expected to have an event-free survival (EFS) of 70% to 80%. Standard-risk patients experience approximately 30% of recurrences.
High risk: Patients with FH Wilms tumor who relapse after therapy with three or more agents. These patients account for 45% to 50% of children with Wilms tumor who relapse and have survival rates in the 40% to 50% range.
Very high risk: Patients with recurrent anaplastic or blastemal-predominant Wilms tumor. These patients are expected to have survival rates in the 10% range, and they experience 10% to 15% of all Wilms tumor relapses.[3,7]