Abstract: Prognostic Analysis and Metastatic Behavior of Breast Cancer SubtypesPeitian MIAO, Zhongsheng TONG, Chunfang HAO, Meng ZHANGCorresponding author: Zhongsheng TONG, E-mail: tonghang@medmail.com.cnDepartment of Breast Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, ChinaAbstract Objective: To analyze the clinical features and survival of patients with metastatic breast cancer ( MBC ) subtypes,and to investgate the relationship between different subtypes and characteristics of metastatic sites. Methods: The clinicalpathologicfeatures and survival time of 422 MBC patients treated in Tianjin Medical University Cancer Institute and Hospital between January2002 and December 2004 were reviewed. SPSS13.0 software was used for statistical analysis. Results: At the end of the last follow-up,186 deaths were recorded. The 5-year survival rate was 55.9 %. The bone, lung, and liver were the most common distant metastaticsites, with 179 cases ( 42.4 % ), 173 cases ( 41.0 % ), and 139 cases ( 32.9 % ), respectively. There were 78 cases ( 18.5 % ) with brainmetastasis, including 12 cases ( 7.0 % ) of luminal A, 6 cases of luminal B ( 9.7 % ), 11 cases ( 15.9 % ) with human epidermal growthfactor receptor 2 ( HER-2 ) overexpression, and 49 cases ( 40.8 % ) of triple negative breast cancer ( TNBC ). The 5-year overall surviv-al rate was 67.4 % in luminal A cases, 66.1 % in luminal B cases, 53.6 % in HER-2 overexpression cases, and 34.2 % in TNBC cases (P = 0.000 ). Conclusion: The bone, lung and liver are the most common sites of MBC. Compared with patients of other subtypes, TN-BC and HER-2 overexpression patients have poorer prognosis and higher potential of brain metastases. Compared with those with me-tastases in other sites, breast cancer patients with brain metastases have poorer survival.Keywords Breast cancer; Metastasis; Prognosis