Background: The neutrophil-to-lymphocyte ratio (NLR) is a strong predictor of mortality in patients with cancer. Similarly, a study in a large series has shown that the newly defined derived NLR (dNLR; neutrophil/leukocyte-lymphocyte ratio) also has prognostic value. The present study retrospectively evaluates the prognostic significance of NLR and dNLR in breast cancer.
Methods: Hematological parameters and clinicopathological data during diagnosis were retrospectively recorded for 1,527 patients diagnosed with breast cancer at Izmir Katip Celebi University Ataturk Research and Training Hospital from January 2006 to December 2011. The cut-off values were determined by calculating the NLR and dNLR of the patients.
Results: The cut-off values were determined as 4 and 2 for NLR and dNLR, respectively. The association between NLR and dNLR assessed by Spearman's rank correlation analysis was 0.935 (P < 0.001). There was a significant difference regarding disease free survival (DFS) and overall survival (OS) in patients with NLR <4 and NLR ≥4 (respectively, P < 0.00, P < 0.001). Similarly, there was a significant difference regarding DFS and OS in patients with dNLR <2 and dNLR ≥2 (respectively, P < 0.001, P < 0.001). Furthermore, NLR and dNLR demonstrated a significant association with the American Joint Committee on Cancer (AJCC) staging (P < 0.001). Assessment using the Cox proportional multivariate model showed that high NLR, pN, pT, luminal A-like, luminal B-like (HER2 positive), basal-like, and AJCC staging are independent prognostic factors.
Discussion: NLR was shown to be better than dNLR in terms of predicting prognosis in patients with breast cancer. However, large prospective studies are required to further demonstrate the prognostic significance of these two values.