Clinical profile and prognosis of metastatic breast cancer (MBC) patients with long-lasting response to eribulin (E): Results of the EXTER study.

e12022 Background: Eribulin, an anti-microtubule agent, has emerged as the only drug showing overall survival benefit at or beyond the third line treatment of MBC. However, no clinical factors are available to identify the group of patients with maximum benefit of treatment with E. The aim of this study was to analyze the clinical profile of MBC patients with longer response to E in the setting of third or subsequent lines of treatment. Methods: We performed an observational, retrospective study in 30 hospitals participating in a national pre-market program of Special Circumstances Access to Eribulin. All consecutive MBC patients treated with E for at least 7 months until Jan-14 were included. Clinical variables, including those related to MBC diagnosis and previous treatment, were collected. Response was evaluated according to RECIST 1.1 criteria. Results: We included 45 patients MBC patients. Median age was 57. Ten patients had stage IV at diagnosis; in the other 35, median time to metastatic recurrence...