Platelet-to-lymphocyte ratio in patients with metastatic breast cancer treated with eribulin

Abstract Background Eribulin is widely used in treating metastatic breast cancer (BC). Higher neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte ratios (PLR) are associated with higher mortality in several cancers. However, the association between BC prognosis and peripheral immune status remains controversial. We quantified the relative effects of NLR and PLR on survival in patients with recurrent/stage IV BC and evaluated their clinical prognostic value. Methods This retrospective study included 156 patients with recurrent/stage IV disease who received eribulin monotherapy at Saitama Medical University International Medical Center. We examined clinicopathological features (peripheral blood findings and biochemical liver and kidney function test results) and conducted univariate and multivariate analyses of the overall survival (OS). Results The 156 eribulin-treated patients had a median follow-up duration of 18.3 months. Before eribulin treatment, patients with absolute lymphocyte count (ALC) > 1500/uL, NLRs < 3.0, and PLRs < 150 had significantly longer OS than those with lower ALC, and higher NLR and PLRs (median OS, 25.5 vs. 15.5 months; p < 0.01; 20.3 vs. 13.6 months, p < 0.01; and 29.2 vs. 14.8 months; p < 0.001, respectively). Patients with anemia (hemoglobin < 10 g/dL) or liver dysfunction (albumin-bilirubin grade 2/3) had significantly shorter OS than those without (p < 0.001, respectively). Multivariate analysis revealed low albumin-bilirubin grade (p < 0.001), high hemoglobin (p < 0.01), and low PLR (< 0.05) as independent factors of longer OS after eribulin administration. Conclusions Low PLR, anemia, and liver dysfunction might be factors associated with prolonged OS in patients with recurrent/stage IV BC on eribulin therapy, and could be clinically useful, as their evaluation requires neither new equipment nor invasive testing.