The Role of Metastasectomy in Patients with Renal Cell Carcinoma with Sarcomatoid Dedifferentiation: A Matched Controlled Analysis

Purpose: Management of metastatic renal cell carcinoma with sarcomatoid dedifferentiation remains a therapeutic challenge with no standard treatment strategies. We evaluated whether metastasectomy has any survival benefit in patients with metastatic sarcomatoid dedifferentiation treated with radical nephrectomy. Materials and Methods: From an institutional database of 273 patients with sarcomatoid dedifferentiation treated with nephrectomy we matched 80 with synchronous and asynchronous metastases for age, ECOG (Eastern Cooperative Oncology Group) performance status, histology and lymph node status. Matched pairs were then retained only if patients who did not undergo metastasectomy were alive at metastasectomy comparable to matched surgical patients to decrease the bias of survival outcomes. Overall survival from nephrectomy was studied using univariable and multivariable proportional hazards regression. Results: Median overall survival was 8.3 (95% CI 6.5-10.5) and 18.5 months (95% CI 11.5-42.9) in patients with synchronous and asynchronous metastases, respectively. Overall survival in patients who underwent metastasectomy for synchronous metastasis compared to nonsurgical patients was 8.4 and 8.0 months (p = 0.35), respectively. Similarly, overall survival in patients with asynchronous metastases treated with metastasectomy compared to the nonsurgical group was 36.2 and 13.7 months, respectively (p = 0.29). On multivariable analysis positive lymph nodes at nephrectomy were associated with an increased risk of death in the synchronous and asynchronous patient subgroups (HR 2.1, 95% CI 1.1-4.0, p = 0.03 and HR 3.3, 95% CI 1.2-9.2, p = 0.02, respectively). Conclusions: In the current study there was no clear evidence of benefit in patients with sarcomatoid dedifferentiation who underwent metastasectomy after nephrectomy. Particularly, the group of patients with pathological lymph node positive disease at nephrectomy had considerably worse survival.