Patient Summary: Outcome of clear cell sarcoma of the kidney (CCSK) treated on the National Wilms Tumor Study-5 (NWTS)
Clear cell sarcoma of the kidney was first described in the 1970's and has a tendency to metastasize to the bone and can relapse long after treatment. The Wilm's Tumor Study has been looking at various combinations of chemotherapy to treat this tumor type over the years. The latest study, NWTS-5, looked at alternating cyclophosphamide and etoposide with the current standard of vincristine/doxorubicin/cyclophosphamide. Patients were also treated with radiation.
Median follow-up at the time of this analysis was 4.6 years. Five year event-free survival (no relapses) was 78.9% and 5-year overall survival (survival with or without relapse) was 88.7%. These results were not different from the NWTS-4 treatment plan, so the addition of cyclophosphamide and etoposide had no effect on outcomes. Etoposide is known to cause secondary cancers down the line, so the authors suggest it would be best to not use this combination given the lack of improvement in outcomes. Further planned studies will look at the addition of carboplatin to the NWTS-4 regimen.