Is eribulin treatment prognostic factor in patients with metastatic breast cancer treated with this drug? Retrospective analysis of a multicentre study.

Purpose: This study aimed to analyze prognostic factors for survival and the reliability and the effectiveness of eribulin therapy in metastatic breast cancer (MBC) patients. Methods: A total of 80 patients treated with eribulin in 12 medical oncology centers in Turkey between 2013-2017 were retrospectively evaluated. Sixteen potential prognostic variables were assessed for analysis. Results: The patients had received a median of 5 prior chemotherapy regimens and a median of 3 eribulin cycles for MBC. Median progression-free survival (PFS) was 5.5 months (95% Cl: 4.1-7.8) and median overall survival (OS) was 11 months (95 % Cl: 6-15). Multivariate analysis showed that eribulin treatment line was shown to have independent prognostic significance for PFS. PFS difference was demostrated in patients who received 3 chemotherapy lines for advanced disease compared to those who had more than 3 chemotherapy lines [median PFS; 3 lines: 8.6 months (6.2-11) and >3 lines: 4.6 months (3.7-4.6) p=0.00]. The clinical benefit rate (CBR) was 52.5 and 35% in patients treated with three lines and with >3 previous chemotherapeutic regimens. Most common toxicities were neutropenia (62.5%), fatigue (52.5%), alopecia (50%) and nausea (37.5%). Conclusions: Eribulin treatment line was identified as indepedent prognostic factor for PFS in MBC patients.