[Efficacy of TS-1 as a Late-Line Treatment for Metastatic Breast Cancer].

: We report 4 female patients with metastatic breast cancer who were administered TS-1 as a late-line treatment and showed favorable outcomes. Their average age was 66.3. The patients, all of whom had undergone prior treatment with both anthracyclines and taxanes, showed intrinsic Luminal A or B subtypes. After administration of TS-1 in the lines of 2 to 9 in metastatic settings, all patients showed a long progression-free survival with a favorable quality of life.