Eribulin efficacy for metastatic breast cancer amongst the real-world treatment pattern

Abstract

Background: Treatments options for metastatic breast cancer (MBC) have become more efficacious and numerous. Eribulin is an active agent for MBC treatment, but the effective usage of this drug is still unclear. Although the usage of eribulin for MBC in Europe is limited to patients who exposed to minimum of two previous chemotherapy regimens including anthracyclines and taxanes in the adjuvant or metastatic setting, there is no such strict limitation in Japan. The purpose of this retrospective study is to evaluate effective usage of erubulin in pretreated metastatic breast cancer patients in daily practice. Patients & methods: Chart review was done for the patients who underwent chemotherapy, which include at least paclitaxel or eribulin for metastatic breast cancer between October 2012 and April 2016 in our single institute. One hundred and fifty patients were included in our cohort. The primary efficacy measure assessed overall survival (OS). Result: Among human epidermal growth factor receptor 2 (HER2) negative patients, 51 received eribulin (eribulin group) and 66 received conventional chemotherapy excluding erubulin (non-eribulin group). The median OS from MBC diagnosis in the eribulin group was 39.0 months compared with 22.7 months in the non-eribulin group [hazard ratio (HR): 0.46, 95%CI 0.29-0.73; p=0.001]. Eribulin seemed to have significant survival benefit in patients with lung metastasis, but not in patients without lung metastasis in our cohort. Same trend was recognized with liver metastasis, or bone metastasis. Conclusion: Eribulin therapy may have a survival benefit in Japanese women with HER2 negative MBC. And may have benefit in MBC patients with lung, liver or bone metastasis.