Early response of C-reactive protein as a predictor of survival in patients with metastatic renal cell carcinoma treated with tyrosine kinase inhibitors.
Pretreatment C-reactive protein (CRP) has been shown to be an independent prognostic factor for metastatic renal cell carcinoma (mRCC) treated with tyrosine kinase inhibitors (TKIs). We further evaluated the early response of CRP after the initiation of TKIs.METHODS
A total of 103 patients (80 men and 23 women) were treated with TKIs for mRCC from 2008-2013. Patients were divided into three groups according to their early CRP kinetics-patients whose baseline CRP levels were <10 mg/L (non-elevated), patients whose baseline CRP levels were ≥10 mg/L and had decreased by >20% at 4 weeks after the initiation of TKIs (early CRP responder), and the remaining patients (non-early CRP responder). The endpoints were progression-free survival (PFS) and overall survival (OS).RESULTS
The median follow-up period was 21 (interquartile range 10-34) months. The numbers of patients classified as non-elevated, early CRP responder, and non-early CRP responder were 62, 19, and 22, respectively. The 1-year PFS rates of patients in the non-elevated, early CRP responder, and non-early CRP responder groups were 50, 23, and 9.7%, respectively (p < 0.001). The 1-year OS rates of patients in these three groups were 79, 62, and 36%, respectively (p < 0.001). In multivariate analysis, the early CRP kinetics assessment was a significant independent factor for PFS and OS.CONCLUSIONS
Early CRP response at 4 weeks is predictive of survival for patients with mRCC treated with TKI.