Significant Association Between Low Baseline Neutrophil-to-Lymphocyte Ratio and Improved Progression-free Survival of Patients With Locally Advanced or Metastatic Breast Cancer Treated With Eribulin But Not With Nab-Paclitaxel

Although eribulin and nab-paclitaxel are chemotherapy agents widely used for locally advanced or metastatic breast cancer (MBC), their predictive factors remain unknown. Because the absolute neutrophil-to-lymphocyte ratio (NLR) is a significant prognostic factor for early-stage breast cancer, we investigated its usefulness in terms of the eribulin or nab-paclitaxel treatment efficacy for MBC.A total of 85 patients with MBC treated with eribulin (n = 59) or nab-paclitaxel (n = 26) were recruited. NLR values were collected at baseline, after 1 cycle, after 2 cycles, and at the end of treatment. The NLR cutoff value was set at 3.The progression-free survival (PFS) of patients with an NLR 3 at baseline (median, 242 days; n = 24) was significantly better than that of patients with an NLR of ≥ 3 (median, 98 days; n = 35; hazard ratio, 0.37, 95% confidence interval, 0.18-0.71; P = .0032). Similarly, the overall survival was marginally significantly better in patients with an NLR 3 who were treated with eribulin (P = .058). However, the NLR was not significantly associated with PFS or overall survival for patients treated with nab-paclitaxel. No significant association was found between the NLR during treatment and PFS in the eribulin group. The significance of the NLR for the efficacy of eribulin was consistent, irrespective of estrogen receptor status, previous anthracycline or endocrine use, and the number of previous chemotherapy regimens.A low NLR at baseline was significantly associated with improved PFS in patients treated with eribulin but not in those treated with nab-paclitaxel. Therefore, the baseline NLR might be clinically useful for selecting patients who would benefit from eribulin.