Elevated preoperative C-reactive protein is associated with renal functional decline and non-cancer mortality in surgically treated renal cell carcinoma: analysis from the INternational Marker Consortium for Renal Cancer (INMARC)

Abstract

Objective: To investigate association of preoperative C-reactive protein (CRP) and non-cancer mortality (NCM) in a cohort of patients undergoing surgery for localised renal cell carcinoma (RCC).

Patients and methods: Retrospective multicentre analysis of patients surgically treated for clinical Stage 1-2 RCC from 2006 to 2017, excluding all cases of cancer-specific mortality. Descriptive analyses were obtained between the pre-treatment normal-CRP (≤5 mg/L) and elevated-CRP (>5 mg/L) groups. The primary outcome was NCM. The secondary outcomes included progression to de novo chronic kidney disease Stages 3-4 (estimated glomerular filtration rate [eGFR] of <60, <45, and <30 mL/min/1.73 m² ). Multivariable analyses (MVA) were performed to assess for risk factors associated with functional decline and NCM, and Kaplan-Meier analysis was used to obtain survival estimates for outcomes.

Results: A total of 1987 patients who underwent radical or partial nephrectomy were analysed (normal-CRP group, n = 963; elevated-CRP group, n = 1024). Groups were similar in age (59 vs 60 years, P = 0.079). An elevated CRP was more frequent in males (36.8% vs 27.8%, P < 0.001), African-Americans (22.6% vs 2.9%, P < 0.001), and in those with a higher median body mass index (30 vs 25 kg/m² , P < 0.001) and larger median tumour size (4.5 vs 3.3 cm, P < 0.001). On MVA, an elevated CRP was independently associated with development of de novo eGFR of <60 mL/min/1.73 m² (hazard ratio [HR] 1.32, P = 0.015), <45 mL/min/1.73 m² (HR 1.41, P = 0.023) and <30 mL/min/1.73 m² (odds ratio 2.23, P < 0.001). The MVA for factors associated with NCM demonstrated increasing age (HR 1.06, P < 0.001), preoperative elevated CRP (HR 2.18, P < 0.001) and an eGFR of <45 mL/min/1.73 m² (HR 1.16; P = 0.021) as independent risk factors. Kaplan-Meier analysis revealed significantly higher 5-year NCM in the elevated-CRP group vs the normal-CRP group (98% vs 80%, P < 0.001).

Conclusions: Pre-treatment elevated CRP was independently associated with both progressive renal functional decline and NCM in patients undergoing surgery for Stage 1-2 RCC. Patients with elevated CRP and Stage 1 and 2 RCC may be considered as having indication for nephron-sparing strategies, which may be prioritised if oncologically appropriate.

Keywords: C-reactive protein; chronic kidney disease; non-cancer mortality; partial nephrectomy; radical nephrectomy; renal cell.