The purpose of this study is to compare whether prophylactic cranial irradiation in patients with advanced triple negative breast cancer who had a response to first line chemotherapy could prolong brain-metastasis free survival.

This is a phase III, randomized, controlled, open, multicenter clinical trial, designed to assess the efficacy and safety of prophylactic cranial irradiation (PCI) in advanced triple negative breast cancer who response to the first line chemotherapy. Compare the PCI group with the observation group to evaluate brain metastasis-free survival,cumulative risk of brain metastases within 1 year,progression-free survival,overall survival,quality of life measured by the The Europe organization for research and treatment of cancer, Quality of life Questionnaire-cancer 30 (EORTC-QLQ-C30) questionnaire score and function of central nervous measured by the The Europe organization for research and treatment of cancer, Quality of life Questionnaire-brain cancer 20 (EORTC-QLQ-BN20) questionnaire score in women with advanced triple negative breast cancer who response to the first line chemotherapy.

Inclusion Criteria:

1. Signed informed consent;
2. Age of 18 to 65 years;
3. Documented advanced breast cancer, clinical and pathological confirmed;
4. Immunohistochemical examination:ER<1%+, progestin receptor (PR)<1%+, HER-2 -/+ or HER-2(++)with negative result of FISH;
5. A response after four to eight cycles of first line chemotherapy;
6. Life expectancy longer than six months evaluated by investigator;
7. A performance status of 0 to 2, according to the criteria of the World Health Organization (with a higher score indicating a poorer performance status)
8. Less than grade 1( Common Terminology Criteria grade version 4.0) of treatment-related toxicities;
9. Adequate baseline organ function.

Exclusion Criteria:

1. History of another malignancy.
2. Pregnancy or gestation
3. Definite diagnosed of central nervous system (CNS)or leptomeningeal metastases
4. Serious cardiac illness or medical condition
5. Known history of related central nervous system or leptomeningeal disease
6. Cognition impairment or suffering from mental illness
7. Demand a long-term oral administration of psychotropic drugs
8. Have a concurrent disease or condition that may interfere with study participation, or any serious medical disorder that would interfere with the subject's safety (for example, active or uncontrolled infection, currently active/requiring anti-viral therapy hepatic or biliary disease)