This 2 arms study will assess the efficacy and safety of the Vinorelbine-Docetaxel combination given as an initial upfront treatment (first line) to all metastatic breast cancer patients enrolled. Patients having a disease control following initial treatment, will be randomized to either oral Vinorelbine maintenance arm or Observation arm. The trial will also compare the efficacy and safety of maintenance oral Vinorelbine versus Observation.