Metastasectomy for metastatic renal cell carcinoma in the era of modern systemic treatment: C-reactive protein is an independent predictor of overall survival.

OBJECTIVE

To define the predictive capability of serum C-reactive protein for a contemporary patient collective undergoing metastasectomy for metastatic renal cell carcinoma with access to modern targeted therapies.

METHODS

A total of 88 patients treated with metastasectomy for metastatic renal cell carcinoma from 2003 to 2014 were evaluated for putative clinicopathological risk factors and survival. Kaplan-Meier analyses, univariate and multivariate testing were carried out. Receiver operating characteristic curve analysis was applied to evaluate available risk stratification instruments for patients undergoing metastasectomy.

RESULTS

Median overall survival for the collective was 66.31 months (95% confidence interval 50.67-135.47; 5-year overall survival 55%). The median preoperative C-reactive protein level was 6.7 mg/L (range 0.1-161.7). A C-reactive protein cut-off value of 5 mg/dL was significantly discriminative of survival (P = 0.029). Median survival in dependence of C-reactive protein accounted for 50.67 months (range 33.86-63.05 months) in the C-reactive protein >5 mg/L group, and 135.47 months in the C-reactive protein ≤5 mg/L group (range 66.31-135.47 months). C-reactive protein elevation >5 mg/L, anemia and surgical margin status were identified as significant predictors of overall survival in univariate analysis. In a multivariate model, resection margin status (P = 0.015) and C-reactive protein elevation (P = 0.038) were confirmed as independent predictive variables.

CONCLUSIONS

Elevated C-reactive protein >5 mg/L was identified as an independent predictor of survival in a contemporary patient collective undergoing metastasectomy for metastatic renal cell carcinoma. Future analyses and risk stratification tools for patients undergoing metastasectomy for metastatic renal cell carcinoma should aim to evaluate and include C-reactive protein. To overcome low patient numbers, multi-institutional studies should be carried out.