Randomized study of Taxane vs TS-1 in metastatic or recurrent breast cancer patients

INTERVENTION: Taxane arm is given one administration chosen from below three pattern of administration by doctor. We repeat it 6 cycles or till cancer becomes worse. (1) Dosetaxel 60‐75mg/m2 (one cycle: 3 or 4 weeks interval adoministration) (2) Paclitaxel 175mg/m2 (one cycle: 3 or 4 weeks interval adoministration) (3) Paclitaxel 175mg/m2 (one cycle: every 3 week administration continuously followed by 1 week rest period) TS‐1 arm is given 40‐60mg/m2 (adjusted to body surface) TS‐1 administration 2 times/day (morning and evening) for 28 days continuously followed by 14 days rest period. Total 6 weeks is regarded as one cycle. We repeated it 4 cycles or till cancer becomes worse. CONDITION: Metastatic or recurrent breast cancer PRIMARY OUTCOME: Overall Survival SECONDARY OUTCOME: Progression‐Free Survival; Time To Treatment Failure ; Adverse Events; Hearth‐Related QOL; Efficacy of medical economy INCLUSION CRITERIA: 1)Histologically proven breast cancer 2)(a)Distant metastasis (Stage IV) in first diagnosis or (b) Proven metastatic or recurrent breast cancer after treatment by distant metastasis 3)At least one assessable lesion 4)No prior chemotherapy 5)ECOG performance status 0‐1 6)(a)No prior Taxane administration or (b)Having passed at least 6 months since last Taxane administration 7)(a)No prior 5‐FU administration or (b)Having passed more than 6 months since last 5‐FU administration 8)Having passed more than 7 days since last hormonal therapy and more than 14 days since last radiation therapy 9)(a)Estrogen receptor(‐) and progesterone receptor(‐) in test of primary or recurrent lesion, (b) Ineffective primary hormonal therapy after metastasis or recurrence or (c)Metastasis or recurrence during postoperative adjuvant hormone therapy or within 6 months after last hormone therapy 10)Neutrophilic leukocyte>=1,500 or WBC>=3,000, PLT>=1