Predictive value of preoperative neutrophil-to-lymphocyte ratio in non-metastatic papillary renal cell carcinoma patients after receiving curative surgery

OBJECTIVE: To determine the predictive value of preoperative neutrophil-to-lymphocyte ratio (NLR) for disease-free survival (DFS) in non-metastatic papillary renal cell carcinoma (pRCC) patients following partial or radical nephrectomy. METHODS: We retrospectively analyzed 315 non-clear cell RCC patients who received curative surgery in our hospital from 2013 to 2018, from which 76 pRCC patients without metastasis (T(1-3)N(0)M(0)) were selected. The receiver operating characteristics (ROC) curve was drawn and an NLR cut-off of 2.5 was set to achieve maximum diagnostic accuracy for predicting DFS. Kaplan-Meier method and the Cox regression model was used to determine the relationship of NLR with DFS. RESULTS: During a median follow-up of 28.0 months (IQR 15.9–42.1, mean 31.4), disease recurred in 12 patients (15.8%) recording a median duration of 14.4 months (IQR 8.6–22.9, mean 16.6). The 5-year DFS was 85.5% and 61.6% for the low (<2.5) and high (≥2.5) NLR groups respectively. According to Kaplan-Meier analysis, DFS was significantly lower in the high NLR group compared with that in the low NLR group (p=0.03). Univariate analysis revealed that high NLR level (HR 3.3, p=0.041), advanced pathological T stage (HR 10.1, p<0.001), larger tumor size (HR 1.2, p=0.008) and radical nephrectomy (HR 5.7, p=0.025) were associated with poor DFS, while multivariate analysis indicated that only advanced pathological T stage (HR 6.9, p=0.010) and high NLR level (HR 3.8, p=0.028) remained as the independent prognostic factors for poor DFS. CONCLUSION: A high preoperative NLR level was an independent prognostic marker for DFS in the patients of non-metastatic pRCC (pT1-3N0M0) following curative surgery. This can be used as an adjuvant tool to select patients for clinical trials or more frequent follow-up strategies.