Presence of sarcomatoid differentiation as a prognostic indicator for survival in surgically treated metastatic renal cell carcinoma

To assess the prognostic significance of sarcomatoid differentiation for surgically treated metastatic renal cell carcinoma (mRCC).

Of the 184 patients with mRCC included, 27 (14.7%) patients presented with sarcomatoid differentiation. The presence of sarcomatoid differentiation was associated with higher rates of non-clear cell histology (P = 0.009), higher Fuhrman grade (P < 0.001), higher rates of presenting tumor necrosis (P = 0.005), worse IMDC risk group (P = 0.022), and MSKCC risk group (P = 0.020). Patients with sarcomatoid differentiation showed shorter median progression-free survival and overall survival. Multivariate analysis identified that sarcomatoid differentiation was independently associated with progression-free survival (hazard ratio [HR]: 2.002, 95% CI 1.047–3.828; P = 0.036) and overall survival (HR: 1.922, 95% CI 1.073–3.445; P = 0.028). Sarcomatoid differentiation remained to be independently associated with inferior PFS (HR: 2.097, 95% CI 1.091–4.030; P = 0.026) and OS (HR: 2.245, 95% CI 1.276–3.951; P = 0.005) for clear cell mRCC.

The presence of sarcomatoid differentiation is independently associated with poor oncologic outcomes for surgically treated mRCC patients. The association remains significant when the subject of study is restricted to clear cell mRCC.