Prognostic Significance of Inflammation-associated Blood Cell Markers in Nonmetastatic Clear Cell Renal Cell Carcinoma

Abstract

Objectives: Our objective was to evaluate the effect of the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), and red blood cell distribution width (RDW) on the survival outcomes of nonmetastatic clear cell renal cell carcinoma (ccRCC).

Materials and methods: We accessed our single-center, urologic-oncologic registry to extract the data for patients who had undergone nephrectomy for nonmetastatic ccRCC. The optimal cutoff for these markers was determined using X-tile software, and survival analyses using Cox regression were performed.

Results: A total of 687 patients had undergone nephrectomy. The optimal cutoffs for NLR, PLR, LMR, and RDW were 3.3, 210, 2.4, and 14.3%, respectively. The NLR, PLR, LMR, and RDW were significantly associated with a larger pathologic tumor size, and stage, more aggressive Fuhrman grade, and the presence of tumor necrosis. After adjusting for age, baseline Eastern Cooperative Oncology Group, pathologic tumor and nodal stage, and Fuhrman grade, only PLR remained an independent prognostic marker for both cancer-specific survival (hazard ratio, 2.69; 95% confidence interval, 1.36-5.33; P = .004) and overall survival (hazard ratio, 2.19; 95% confidence interval, 1.36-3.50; P = .001). When the PLR was included with the Leibovich score and University of California, Los Angeles, integrated staging system, the Harrell's c-index increased from 0.854 to 0.876 and 0.751 to 0.810, respectively, for cancer-specific survival at 5 years after nephrectomy. When risk stratified by the Leibovich risk group and UCLA integrated staging system, PLR was a significant prognostic factor only within the intermediate- to high-risk groups.

Conclusions: PLR is a robust prognostic marker in nonmetastatic ccRCC that clearly outperforms other inflammatory indexes in those who had undergone nephrectomy. However, its prognostic effect was limited in the low-risk category of ccRCC.

Keywords: Lymphocyte/monocyte ratio; Neutrophil/lymphocyte ratio; Platelet/lymphocyte ratio; Red-cell distribution width; Survival outcomes.