Due to a rising number of elderly patients, fit for chemotherapy, investigating a well-tolerated and effective first line treatment is warranted. In this specific population often there are contra-indications for the use of standard first line drugs like anthracyclines and taxanes due to comorbidities (e.g. cardiac impairment or Peripheral neuropathy). Response rates in first line treatment with taxanes and anthracyclines usually do not exceed 30%. Eribulin has shown a response rate of 29% and a clinical benefit rate (corresponding to the investigators primary endpoint) of 52% in first line, so the investigators expect similar efficacy, but less toxicity.