Neutrophil-to-lymphocyte ratio as a prognostic factor for patients with metastatic or recurrent breast cancer treated using capecitabine: a retrospective study

Background: Eribulin or capecitabine monotherapy is the next cytotoxic chemotherapy option for patients with metastatic or recurrent breast cancer who have previously received an anthracycline or a taxane. However, it is unclear what factors can guide the selection of eribulin or capecitabine in this setting, and prognostic factors are needed to guide appropriate treatment selection. The neutrophil-to-lymphocyte ratio (NLR) is a prognostic factor for eribulin-treated patients, although it is unclear whether it is a prognostic factor for capecitabine-treated patients. Therefore, we analysed the ability of the NLR to predict oncological outcomes among patients who received capecitabine after previous anthracycline or taxane treatment for breast cancer. Methods: We retrospectively reviewed the medical records of patients with metastatic or recurrent breast cancer who had previously received anthracycline or taxane treatment at the National Cancer Center Hospital between 2007 and 2015. Patients were included if they received eribulin or capecitabine monotherapy as first-line, second-line, or third-line chemotherapy. Analyses of overall survival (OS) and progression-free survival (PFS) were performed according to various factors. Results: Between 2007 and 2015, we identified 125 eligible patients, including 46 patients who received only eribulin, 34 patients who received only capecitabine, and 45 patients who received eribulin and capecitabine. The median follow-up period was 19.1 months. Among eribulin-treated patients, an NLR of <3 independently predicted better OS. Among capecitabine-treated patients, an NLR of <3 independently predicted better PFS but not better OS. In addition, a lymphocyte-to-monocyte ratio of ≥5 was associated with better PFS and OS. Conclusions: To the best of our knowledge, this is the first study to evaluate whether the NLR is a prognostic factor for capecitabine-treated patients with metastatic or recurrent breast cancer. However, the NLR only independently predicted PFS in this setting, despite it being a useful prognostic factor for other chemotherapies.