Eribulin Suppresses New Metastases in Patients With Metastatic Breast Cancer

Background/Aim: This study aimed to investigate the progression type of metastatic breast cancer (MBC) in patients undergoing eribulin chemotherapy. Materials and Methods: We retrospectively investigated the cases of 66 consecutive patients with MBC who underwent eribulin chemotherapy. Results: A total of 15 patients (22.7%) received eribulin as a 3rd-line or later treatment, and 17 (25.8%) received eribulin as a 1st-line treatment. The overall response was complete response in 0 (0%), partial response in 15 (22.7%), stable disease in 27 (40.9%), and progressive disease in 24 (36.4%) patients. By the time of data cut-off, time to treatment failure (TTF) events had been observed in 60 patients (90.9%), among whom, 15 (25%) had disease progression due to NM, and 45 (75%) had disease progression due to PL. In the regimen before eribulin administration, among 49 patients, 24 (49.0%) had disease progression due to NM. Luminal-type patients and those with triple-negative breast cancer exhibited a similar tendency, i.e., the rate of NM was lower in the patients treated with eribulin. The rate of NM was lower in the patients treated with eribulin in the 1st-line setting than that in patients treated with eribulin as a later treatment. Conclusion: Eribulin has a potential antitumor mechanism to prevent new metastasis. Eribulin may be effective against both the epithelial-mesenchymal transition (EMT) process and new metastasis.