Prediction of early progression of metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitor.

Sarcomatoid differentiation, hypercalcemia, an elevated serum CRP level, and presence of liver metastasis were associated with primary refractory disease in mRCC patients receiving first-line TKI therapy. These results provide clinicians with useful information when selecting a first-line therapeutic option for mRCC patients.