Development and validation of nomograms and integrated software incorporating preoperative C-reactive protein level for prognostic prediction of nonmetastatic clear cell renal cell carcinoma: Results from the International Marker Consortium for Renal Cancer (INMARC) Registry

Preoperative C-reactive protein (CRP) is a valuable prognostic biomarker in nonmetastatic clear cell renal cell carcinoma (nmccRCC). Incorporation of CRP into prognostic models may improve the prediction of oncologic outcomes. Herein, we aimed to develop and validate prognostic nomograms and an integrated software incorporating preoperative CRP level in nmccRCC. An international multi-institutional database was retrospectively analyzed for nmccRCC patients undergoing surgery. A total of 2284 patients were enrolled and randomly allocated to training (n = 1599, 70%) and validation (n= 685, 30%) cohorts. Nomograms predicting overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival (RFS) were developed in the training cohort using multivariable Cox regression, including preoperative CRP levels and other clinical factors. An integrated software was also created. The validation cohort was used to assess the performance of these nomograms. Following a median follow-up of 5.9 years, 318 (13.92%) patients died of any cause, 109 (4.77%) died of renal cancer, and 282 (12.35%) developed recurrence. The median (interquartile range) preoperative CRP level was 1.90 (0.80–5.68) mg/L. A high CRP level was independently associated with worse OS, CSS, and RFS. The nomograms and integrated software incorporating CRP significantly improved prediction accuracy compared with CRP alone. The C-indices for nomograms were 0.74 (95%CI, 0.69–0.80) for OS, 0.87 (0.82–0.93) for CSS, and 0.77 (0.71–0.82) for RFS in the validation cohort. Acceptable calibration was demonstrated at 12/36/60 months for OS, CSS, and RFS. The prognostic nomograms and the user-friendly integrated software incorporating preoperative CRP level may facilitate individualized risk stratification and treatment planning for patients with nmccRCC.