Preoperative neutrophil to lymphocyte ratio as a predictor for pathologic sinus fat invasion in renal cell carcinoma of ≤7cm with presumed sinus fat invasion on preoperative imaging

Abstract

Purpose: To evaluated whether preoperative neutrophil to lymphocyte ratio (NLR) could predict pathologic sinus fat invasion (SFI) in the patients with renal cell carcinoma (RCC) which is smaller than 7cm and presumed to invade renal sinus fat preoperative imaging. Materials and methods: We reviewed the medical records of patients who underwent nephrectomy for non-metastatic RCC smaller than 7cm between November 2005 and May 2014. Among 1311 patients, patients without SFI in preoperative imaging, had unavailable preoperative data and had factors affect NLR were excluded, and 476 patients were involved in this study. We investigated age, gender, body mass index (BMI), hypertension, smoking and preoperative NLR. We used logistic regression analysis to assess whether these factors are associated with pathologic SFI. Results: Cut off value of NLR was set as 1.98 by receiver operation characteristic curve. 93 patients were confirmed to have pathologic SFI. Patients with SFI had larger tumor size in preoperative imaging and higher preoperative NLR. And in the SFI group, pathologic tumor size was larger, more frequent renal vein involvement and higher Fuhrman nuclear grade. In univariate analysis, age (OR 1.019, p=0.05), clinical tumor size (OR 1.645, p<0.001), collecting duct involvement (OR 4.052, p=0.008) and high NLR (OR 2.087, p=0.002) were associated with SFI. In multivariate analysis, high NLR (OR 2.032, p=0.004) was independent prognostic factor of SFI with clinical tumor size (OR 1.586, p<0.001) and collecting system involvement (OR 3.957, p=0.011). Conclusions: Preoperative NLR is related with pathologic SFI in the patients with renal cell carcinomas of 7cm or less presumed SFI on preoperative imaging. However, the role of NLR to predict SFI seems to be limited.