Prognostic effect of preoperative red cell distribution width on the survival of patients who have undergone surgery for non-small cell lung cancer

Red cell distribution width (RDW) is a prognostic factor for various malignancies, including colorectal, breast and lung cancer. The effect of preoperative RDW on the prognosis of patients who have undergone surgery for non-small cell lung cancer (NSCLC) was investigated in the present study. This retrospective, single-institution study included consecutive patients who had undergone complete NSCLC resection between January 2006 and December 2013 at the Department of Thoracic Surgery of Kansai Medical University Hospital (Hirakata, Japan). The overall and recurrence-free survival rates were compared using univariate and multivariate Cox proportional hazard models. A stepwise backward elimination method with a probability level of 0.15 was performed to select the most powerful outcome predictor sets. A total of 338 cases with NSCLC were analyzed. Of these, 25 had high RDWs (≥50 fl) and 313 had low RDWs (<50 fl). The 5-year overall survival rates in patients with high and low RDWs were 0.40 [95% confidence interval (CI): 0.21-0.58] and 0.80 (95% CI: 0.76-0.84), respectively, and the recurrence-free survival rates were 0.48 (95% CI: 0.25-0.68) and 0.70 (95% CI: 0.64-0.75), respectively. High RDW was identified as an independent prognostic factor for overall survival [hazard ratio (HR)=2.29; 95% CI: 1.3-4.01; P=0.004) but not for recurrence-free survival (HR=1.70; 95% CI: 0.93-3.12; P=0.085) by univariate and multivariate analysis. A high preoperative RDW was an independent predictor of poor prognosis in patients who had undergone radical resection of NSCLC. Therefore, patients with high RDW should be carefully monitored postoperatively, regardless of the disease stage.