Relationship between red cell distribution width and prognosis in patients with breast cancer after operation: a retrospective cohort study

We retrospectively enrolled 825 breast cancer patients, who was primarily diagnosed in our hospital between January 2009 and December 2014 and explored the relationship between red blood cell distribution width (RDW) and long-term prognosis in patients with breast cancer. There were 412 patients with high RDW (RDW > 13.82) and 413 patients with low RDW (RDW ≤ 13.82). Compared with low RDW group, the high w group has large tumor size (the rate of tumor size >2 cm: 60.7 vs 44.8%, P=0.013). The rate of lymph node metastases was higher in the high RDW group thaten that in the low RDW group (62.1 vs 45.8%, P=0.000). RDW was positively associated with tumor stage. The high RDW tended to be advanced stage (P=0.000). Compared with low RDW group, the high RDW group tended to be higher lymphocyte count (P=0.004), elevated fibrinogen (P=0.043), and elevated high-sensitivity C-reactive protein (P=0.000). The Kaplan-Meier analysis indicated elevated RDW was positively associated with disease-free survival (DFS) (P=0.004) and overall survival (OS) (P=0.011). The multivariate Cox regression analysis indicated that the high RDW group had poorer OS (Hazard risk [HR] = 2.43; 95% CI: 1.62-3.21; P=0.024) and DFS (HR = 1.89; 95% CI: 1.28-3.62; P=0.000) compared with low RDW group. The present study found that high pretreatment RDW levels in breast cancer patients were associated with poor OS and DFS. RDW could be a potential predictive factor in differential diagnosis of poor prognosis from all patients.