Chemotherapy is offered to almost all patients with metastatic breast cancer. Optimization of treatment has four major goals: (1) To improve access to chemotherapy. Orally active chemotherapy is an attractive option for those patients when access to hospital is limited by financial considerations, long journeys or patient reluctance. In the past, only alkylating agents (cyclophosphamide, chlorambucil, melphalan) could be administered orally. The activity (first- and second-line) of Xeloda (capecitabine) with limited side effects and the development of oral vinorelbine and anthracyclines should improve access to chemotherapy and also concentrate further interest on treatment with long-term administration of cytotoxic agents. (2) To improve response rates and duration in first-line treatment. Response rates have been increased by the use of combinations of taxoids and anthracyclines and/or alkylating agents and/or fluoropyrimidines (>60-70% with complete remission in 10-15% of patients). There is increasing interest in sequential use of active agents or combinations at their optimal doses. Nevertheless, such 'induction regimen' fail to prolong response duration (rarely longer than 9-12 months). The use of less-toxic maintenance chemotherapy regimens increases response duration and disease-free survival. Such maintenance regimens could be used on an outpatient basis and will be further simplified by the availability of active oral agents such as the novel fluoropyrimidine Xeloda. (3) To increase cure rates. This can only be considered with first-line treatment in selected patients (long disease-free interval, minimal number of visceral sites and ability to tolerate high-dose chemotherapy). The completed studies with high-dose chemotherapy and hematopoietic stem cell support have, in fact, shown only a minimal effect on cure rates. Incorporation of very active agents such as taxoids and use of multicycle high-dose therapy may improve these results. (4) To offer alternative active regimens in second and subsequent metastatic progression. Taxoids, vinorelbine and, more recently, Xeloda all achieve a 20-40% response rate in these situations. The reintroduction of agents previously used for adjuvant or first-line therapy can also be considered.