A prospective, multicenter, randomized, open-label study of fulvestrant verses capecitabine as maintenance therapy after first-line combined-chemotherapy in patients with hormone receptor-positive, HER2-negative advanced breast cancer

INTERVENTION: Active Comparator:capecitabine;Experimental group:fulvestrant; CONDITION: Breast Cancer PRIMARY OUTCOME: progression‐free survival; SECONDARY OUTCOME: overall survival;objective response rate;clinical benifit rate;the rate of adverse events;Quality of life 1(QOL1);Quality of life 2(QOL2); INCLUSION CRITERIA: 1. Histologically diagnosis of adult female advanced breast cancer (aged 18 ‐ 80 years old), not suitable to accept surgery or radiotherapy for healing; 2. Histologically diagnosis of hormone receptor positive (ER and/or PR+), HER2 negative breast cancer(ER positive: immunohistochemistry (IHC) >1% tumor cell staining; PR positive: immunohistochemistry (IHC) >1% tumor cell staining; HER‐2 negative: immunohistochemistry 0, 1+, or 2+ while FISH/CISH negative); 3. Patients have completed 4‐8 cycles first‐line combination chemotherapy for metastatic breast cancer without disease progress (CR/PR/SD); 4. WHO performance status 0‐1, Life expectancy > 3 months; 5. Imaging examination within 3 weeks before enrollment are needed (can be check at the local Grade IIIA hospitals), to assess the tumor lesions before maintenance treatment; 6. Treatment‐related toxicity at randomization should be relieved to NCI CTCAE (version 4.03) = grade 1 (except alopecia o