Outcomes of Adults with Ewing Sarcoma Family of Tumors (ESFT) of the Kidney: A Single-Institution Experience

Background: Ewing sarcoma family of tumors (ESFT) of the kidney are exceedingly rare. Given the rarity of this neoplasm and the complexity associated with its management, information regarding treatment and outcome is warranted. Materials and Methods: We conducted a retrospective study of patients with ESFT of the kidney who were treated at MDACC between January 1, 2001 and January 1, 2011. Descriptive statistics were used. Results: Thirteen patients were identified (median age, 33 y; male:female 11:2). Common presenting symptoms were back pain, flank pain, and hematuria. Six patients had metastatic disease at presentation. Initial diagnostic biopsy was performed in 6 patients. Immunohistochemistry showed strong positivity for CD99 (mic2) and cytogenetic analysis demonstrated evidence of EWSR1 fusion gene in 8 cases. Nine patients underwent nephrectomy. Frequently used chemotherapy regimens consisted of vincristine, doxorubicin, and ifosfamide. Median overall survival was 17.2 months. Three patients were alive at the time of analysis, at 2, 7, and 11 years from diagnosis (the latter without evidence of disease). Conclusions: Renal ESFT carry a guarded prognosis with limited response to therapy and short median overall survival. For patients with metastatic disease, diagnostic biopsy and sarcoma-based chemotherapy regimens are recommended as upfront therapeutic strategy. The role of nephrectomy in the metastatic setting is unclear. Future studies with novel therapies are needed.