Cytoreductive nephrectomy for kidney cancer with sarcomatoid histology--is up-front resection indicated and, if not, is it avoidable?

PURPOSE: Cytoreductive nephrectomy has a survival advantage in select patients. Patients with sarcomatoid features are known to have poor outcomes. We reviewed the role of surgery in this population to see if these patients could be identified preoperatively.
MATERIALS AND METHODS: Cytoreductive nephrectomy cases identified as having sarcomatoid features or spindle cells were reviewed. The histology, grade, and the presence and percentage of sarcomatoid elements were recorded. Clinicopathological characteristics, survival and systemic therapy were compared to cases without sarcomatoid histology.
RESULTS: A total of 62 tumors with sarcomatoid histology were identified, accounting for 14.9% of the 417 patients undergoing cytoreductive nephrectomy. The percentage of sarcomatoid transformation widely varied with a range of 2% to 100% and a mean/median of 49.8%/50%. An increased percentage of sarcomatoid features is associated with a worse prognosis. Patients with and those without sarcomatoid features had similar clinical characteristics. In the sarcomatoid group a higher T stage (p <0.001) and increased incidence of nonclear cell histology (p <0.001) were noted. Median survival of patients with sarcomatoid features was 4.9 vs 17.7 months for nonsarcomatoid histology (p <0.001). Use of postoperative therapy was significantly worse for patients with sarcomatoid histology.
CONCLUSIONS: Patients with sarcomatoid histology undergoing cytoreductive nephrectomy have a dire prognosis despite aggressive surgery and postoperative therapy. The variability in the sarcomatoid component and the lack of specific clinical features make preoperative identification challenging. Research should focus on identifying biomarkers for this subset of tumors that may allow up-front systemic therapy with surgery reserved for responding patients.