Supplementary Material for: Preoperative C-Reactive Protein Values as a Potential Component in Outcome Prediction Models of Metastasized Renal Cell Carcinoma Patients Receiving Cytoreductive Nephrectomy

Purpose: To validate preoperative C-reactive protein (CRP) levels as a prognostic marker for survival in a metastasized renal cell carcinoma (mRCC) patient cohort receiving cytoreductive nephrectomy (CN). Patients and Methods: By chart review, 146 mRCC patients receiving CN at our tertiary referral centre from 1997 to 2015 were identified retrospectively. All relevant clinicopathological features including laboratory parameters were collected and correlated to overall survival, progression-free survival and cancer-specific survival (CSS). The mean follow-up was 23 months (range 1-168 months). Results: Besides the already established scoring systems like the MSKCC criteria, an elevated preoperative CRP level (≥0.5 mg/dL) was an independent predictor of CSS in our study group including the chosen postoperative adjuvant therapies (TKI vs. immunotherapy vs. others). With regard to morbidity, patients with a good performance status, small tumour size and adequate renal function/haematopoiesis experienced less complication rates, thereby profiting more from CN. Conclusions: Our data provide indication that preoperative CRP levels should be implemented in nomograms regarding the outcome prediction in mRCC to identify candidates likely to profit from CN.