Neutrophil-to-Lymphocyte Ratio Predicts Pathological Renal Sinus Fat Invasion in Renal Cell Carcinomas of ≤7 cm with Presumed Renal Sinus Fat Invasion

Computed tomography (CT) is the most useful diagnostic modality for staging renal cell carcinoma (RCC). However, CT is limited in its ability to predict renal sinus fat invasion (SFI). Here, we aimed to evaluate whether preoperative neutrophil-to-lymphocyte ratio (NLR) could predict pathological SFI in patients with RCC of ≤7 cm for whom preoperative imaging reveals potential renal SFI. We reviewed the medical records of 1311 patients who underwent extirpative renal surgery for non-metastatic RCC of ≤7 cm between November 2005 and December 2014. After excluding patients with no SFI in preoperative imaging, unavailable preoperative data, and morbidity affecting inflammatory markers, a total of 476 patients were included in this study. Multivariate logistic regression analysis was used to evaluate predictors of pathological SFI. We implemented a cut-off value of 1.98, which was calculated by ROC analysis to obtain high (≥1.98) and low (