Intratumor C-Reactive Protein as a Biomarker of Prognosis in Localized Renal Cell Carcinoma

Purpose: Serum C-reactive protein has been shown to have prognostic value in localized and metastatic renal cell carcinoma. However, the prognostic value of intratumor C-reactive protein remains unknown. Materials and Methods: A total of 95 patients with resected, clinically localized (T1-T4N0M0) clear cell renal cell carcinoma were followed postoperatively. Intratumor C-reactive protein expression was assessed in surgical specimens using immunohistochemical analysis. Patients were categorized by staining intensity into low risk (staining 0 to 1), intermediate risk (staining 2) and high risk (staining 3) groups. Kaplan-Meier and multivariate Cox regression analyses were used to examine overall survival across patient and disease characteristics. Variables examined in multivariate Cox regression analysis included T stage, Fuhrman nuclear grade, tumor size, preoperative serum C-reactive protein and intratumor C-reactive protein staining. Results: Followup extended up to 46 months with a mean (SD) of 29.8 (11.0) months. Twelve patients (12.6%) died during followup. Of all tumors 49.5%, 25.3% and 25.3% were graded by intratumor C-reactive protein staining as low risk (0 to 1), intermediate risk (2) and high risk (3), respectively. After controlling for variables significant on univariate analysis, patients in the high risk (3) group experienced a 27-fold increased risk of overall mortality compared to those in the low risk (0-1) group (HR 27.767, 95% CI 1.488-518.182). After adjusting for tumor staining, preoperative serum C-reactive protein was not a significant predictor of overall survival (p = 0.741). Conclusions: Intratumor C-reactive protein may be a robust biomarker of prognosis in patients with localized renal cell carcinoma.