The usefulness of red blood cell distribution width and its ratio with platelet count in breast cancer after surgery and adjuvant treatment: a retrospective study

BACKGROUND: To date, red blood cell distribution width (RDW) and RDW-to-platelet count ratio (RPR) have been investigated for their association with cancer. This study aimed to investigate the prognostic value of RDW and RPR in breast cancer before and after treatment. METHODS: We retrospectively enrolled 395 patients with breast cancer, who were diagnosed between December 2009 and December 2015 and analyzed the association between RDW, RPR, and long-term prognosis. We also compared the RDW and RPR values with the pathologic parameters of breast cancer. The cutoff values for before-treatment RDW, RPR value, after-treatment RDW, and RPR were determined using receiver operating characteristic (ROC) curve analysis by identifying the highest Youden index. RESULTS: In the before-treatment state, no significant disease-free survival (DFS) or overall survival (OS) was found in the RPR and RDW values. However, we found that elevated after-treatment RPR and RDW were significant prognostic factors for DFS, with hazard ratios (HRs) of 2.233 [95% confidence interval (CI): 1.073–4.649; P=0.032] and 2.067 (95% CI: 1.085–3.937; P=0.027). Kaplan-Meier analysis indicated that the after-treatment RPR and RDW groups had poor OS (HR =30.461; 95% CI: 5.138–180.575; P<0.001) compared with the lower after-treatment RPR and RDW groups. In particular, when the RPR and RDW were in the lower group before the treatment and became elevated after the treatment, it showed a remarkably significant result for OS, with HR 132.6 (95% CI: 3.689–4,767.341; P=0.007) and 10.119 (95% CI: 1.853–55.249; P=0.008). CONCLUSIONS: Thus, after-treatment RPR and RDW could have prognostic value for breast cancer after surgery and adjuvant treatment.