Outcomes of Patients with Renal Cell Carcinoma and Sarcomatoid Dedifferentiation Treated with Nephrectomy and Systemic Therapies: Comparison between the Cytokine and Targeted Therapy Eras

Purpose We studied overall survival and prognostic factors in patients with sarcomatoid renal cell carcinoma treated with nephrectomy and systemic therapy in the cytokine and targeted therapy eras. Materials and Methods This is a retrospective study of patients with sarcomatoid renal cell carcinoma who underwent nephrectomy and received systemic therapy at our center in the cytokine era (1987 to 2005) or the targeted therapy era (2006 to 2015). Multivariate regression models were used to determine the association of covariables with survival. Results Of the 199 patients with sarcomatoid renal cell carcinoma 167 (83.9%) died (median overall survival 16.5 months, 95% CI 15.2–20.9). Survival of patients with clear cell histology was significantly longer vs those with nonclear cell histology (p = 0.034). Patients with synchronous metastatic disease had significantly shorter survival than patients with metachronous metastatic disease (median 12.1 vs 23.3 months, p = 0.0064). Biopsy of the primary tumor or a metastatic site could detect the presence of sarcomatoid features in only 7.5% of cases. Although a significant improvement in survival rate was observed in the first year in patients treated in the targeted therapy era (p = 0.011), this effect was attenuated at year 2, disappeared at years 3 to 5 after diagnosis and was not evident in patients with poor risk features. Conclusions Patients with sarcomatoid renal cell carcinoma still have poor prognosis with no clear long-term benefit of targeted therapy. This underscores the need to develop more effective systemic therapies for these patients.