CRP Levels Predict Survival in RCC Patients on Dialysis

Preoperative levels of C-reactive protein (CRP) may be as predictive of outcomes as pathological TNM stage or tumor grade for prognosis in patients on hemodialysis with renal cell carcinoma and end-stage renal disease who undergo nephrectomy.

“These results suggest that this blood-based factor can also become a potent biomarker for predicting outcome following nephrectomy in dialysis patients,” Kenji Omae, MD, of Tokyo Women’s Medical University, and colleagues wrote in Urologic Oncology. “This is the first study, to our knowledge, assessing an association between serum CRP levels and prognosis of malignancy in dialysis patients.”

Prior research had already established a possible relationship between CRP and outcomes in multiple malignancies, including renal cell carcinoma. In this study, Dr. Omae and colleagues wanted to explore if this relationship also existed in patients who are dialysis dependent.

The researchers evaluated outcomes from 315 patients with end-stage renal disease who required dialysis and underwent nephrectomy for renal cell carcinoma between 1982 and 2013. They evaluated preoperative CRP levels and classified patients as having elevated levels if the CRP was greater than 0.5 mg/dL. The median follow-up was 51 months.

Data showed that 23.8% of patients had elevated CRP levels prior to surgery. These patients were more likely to be older, have a poorer performance status, and have more advanced disease.

Of the total cohort, 25.4% of patients had died from some cause and 9.2% died from their cancer. Data revealed that patients with an elevated preoperative CRP level had significantly worse cancer-specific survival (P < .0001). Specifically, the 5-year cancer-specific survival rate was 69.9% for patients with CRP greater than 5 mg/dL compared with 95.2% for patients with normal levels. Preoperative CRP level was independently predictive of cancer-specific survival (HR = 3.47; P = .0098).

“Without a preoperative CRP level, the c-index for the prediction of CSS rate of the base model with standard pathological prognostic factors was 65.3%,” the researchers wrote. “The addition of CRP level improved the accuracy of the base model to 66.8% (gain in predictive accuracy = 1.5%).”

The researchers also examined whether postoperative CRP level normalization affected survival. Sixty-seven patients had post-operative CRP level information available and 55.2% had normal levels. Patients with normal levels had significantly better cancer specific survival than the patients whose postoperative CRP levels did not normalize.

“These results support the hypothesis that a serum CRP level, a particular nonspecific marker of systemic inflammation, might reflect tumor burden or the aggressiveness of end-stage renal disease-renal cell carcinoma in dialysis patients,” the researchers wrote.