Utility of Follow-up With Absolute Lymphocyte Count in Patients Undergoing Eribulin Treatment for Early Detection of Progressive Advanced or Metastatic Breast Cancer.

Abstract

Eribulin, a non-taxane microtubule inhibitor, improves the tumor immune microenvironment via vascular remodeling. Systemic peripheral immune markers such as absolute lymphocyte count (ALC) and neutrophil-to-lymphocyte ratio (NLR) have been reported as prognostic factors of patients treated with eribulin. However, the usefulness of the longitudinal changes of these blood parameters during eribulin treatment remains unknown. A total of 97 patients with locally advanced or metastatic breast cancer treated with eribulin were recruited. ALC and NLR values were collected at each cycle of treatment. The correlation between ALC and NLR and prognosis and antitumor effects was retrospectively evaluated. Progression-free and overall survival for patients with a base line ALC ≥1,500/μl was significantly better than that for those with a lower ALC (p=0.049 and p=0.004, respectively). The mean ALC in the non-progressive disease (PD) group increased, while that in the PD group slightly decreased over time. A low ALC at the last cycle was significantly correlated with PD (p=0.030). Of the 64 patients with PD, 47 were classified as having progression due to a pre-existing lesion (PPL), and 17 patients were classified as having progression due to new metastasis (PNM). The mean ALC for the PPL group slightly increased during eribulin treatment, while that for the PNM group decreased. Eribulin treatment may have improved the immune status in eribulin responders. Monitoring ALC values may be useful for early assessment of response to therapy.