Study of TS-1 as 2nd Line Treatment in Patients With Advanced Metastatic Breast Cancer

Inclusion Criteria:

• Age: 18-75 years old female.
• ECOG status: 0-2.
• Life expectancy of ≥ 3 months.
• Histologic or cytologic diagnosis of breast cancer.
• Progression after receiving one standard prior chemotherapy regimen for recurrent or metastatic lesion except an endocrine regimen.
• At least one measurable lesion of >=2 cm (>=1 cm on spiral CT scan)according to RECIST (v1.1).

• Adequate organ functions:

  • Hematopoietic: Hemoglobin ≥90g/L, Absolute neutrophil count ≥1.5×10^9/L, Platelet count ≥80×10^9/L.
  • Biochemistry: TBil ≤1.5 times upper limit of normal (ULN), AST and ALT ≤2.5× ULN(≤5x ULN if due to liver metastases), Creatinine ≤1.0×ULN and Creatinine clearance >50 ml/min.
• Women with children potential must have negative pregnancy tests 7 days prior to enrollment and be willing to practice acceptable methods of birth control during the study and 8 weeks after last drug administered.
• Ability to take oral medication .
• Signed informed consent.

Exclusion Criteria:

• Pregnancy or lactation or no effective contraception in fertile patients.
• Prior treatment with 5-FU or drugs of same class(excluding patients that relapsed more than one year after adjuvant therapy).
• Less than 4 weeks since prior investigational agents.
• conditions impacting oral drug taking or absorption (e.g. inability to swallow, gastrointestinal resection, chronic diarrhea, intestinal obstruction).
• Organ invasion with rapid progression(e.g. lesions exceeding half of Liver or Lung).
• CNS or psychiatric disorders.
• Allergic to 5-FU.
• Only with bone metastases and no measurable lesions.
• Clinically significant heart diseases (e.g.congestive heart failure, ventricular arrhythmia, myocardial infarction) before enrollment.
• Serious peptic ulcer disease or digestive disorders.
• Bone marrow (Hemoglobin <90g/dl, ANC <1.5×10^9/L, Platelet count <75×10^9/L).
• Renal function disorder (Creatinine >1.0×ULN).
• Liver function disorder (TBil >1.5×ULN).
• Uncontrolled brain metastases.
• Noncompliance with the study protocol.