The Preoperative Neutrophil-to-lymphocyte Ratio is a Novel Biomarker for Predicting Worse Clinical Outcomes in Non-muscle Invasive Bladder Cancer Patients with a Previous History of Smoking

Purpose: We speculated that a heterogeneous population of non-muscle invasive bladder cancer (NMIBC) patients with a previous history of smoking may be more precisely stratified by a biomarker associated with tumor aggressiveness and then focused on the preoperative neutrophil-to-lymphocyte ratio (pre-NLR), which is a simple index of systemic inflammation. Methods: Our study population comprised 605 patients initially diagnosed with NMIBC at our 3 institutions between 1995 and 2013. We analyzed the relationships between pre-NLR levels and clinical outcomes in NMIBC. A pre-NLR level of ≥2.2 was defined as elevated according to a calculation by a receiver-operating curve analysis. Results: In overall, a total of 296 patients (48.9 %) had pre-NLR ≥ 2.2, and the pre-NLR level was one of independent risk factors for tumor recurrence and stage progression. Among 344 patients with a previous history of smoking, 184 (53.5 %) had pre-NLR ≥ 2.2 and the pre-NLR level was one of independent risk factors for tumor recurrence and stage progression. The 5-year recurrence-free survival and progression-free survival rates in patients with pre-NLR < 2.2 were 66.3 and 97.5 %, respectively, which were significantly higher than those in their counterparts (31.7 and 90.4 %, p < 0.001). In either subgroup of patients who were current smokers (N = 175) or former smokers (N = 169), the pre-NLR level was the only independent risk factor for tumor recurrence. The pre-NLR level was not associated with tumor recurrence or stage progression in 261 nonsmoking patients. Conclusions: Pre-NLR levels may be a useful marker for identifying worse clinical outcomes in NMIBC patients, particularly those with a previous history of smoking.