Objective:Triple-negative breast cancer(estrogen receptor-negative,progesterone receptor-negative and Her2-negative) can be classified into two subtypes:basal and non-basal phenotype.And the basal phenotype is associated with poor outcome.The purpose of this study was to figure out the differences of clinicopathological characters and related factors of prognosis between these two subtypes.Methods:Immunohistochemical staining was performed for the CK5/6,CK17 basal markers and EGFR on biopsy samples from 40 triple-negative patients and the clinicopathology features of these samples were investigated.Results:Seventy percent of the patients were diagnosed as the basal phenotype.Compared with the non-basal phenotype,the basal phenotype lesions were significantly larger in diameter with a high nuclear grade.In the node-negative group the basal phenotype clearly showed the same clinicopathological differences.There was statistically significant concordance among all three antibodies.Conclusion:Expression of basal markers identifies a biologically and clinically distinct subgroup of TN tumors,justifying the use of basal markers to define the basal or the non-basal phenotype.It is important to help the doctor deciding the therapeutic strategy for patient with triple-negative breast cancer. Objective: Triple-negative breast cancer (estrogen receptor-negative, progesterone receptor-negative and Her2-negative) can be classified into two subtypes: basal and non-basal phenotype. And the basal phenotype is associated with poor outcome. The purpose of this study was to figure out the differences of clinicopathological characters and related factors of prognosis between these two subtypes.Methods: Immunohistochemical staining was performed for the CK5 / 6, CK17 basal markers and EGFR on biopsy samples from 40 triple-negative patients and the clinicopathology features of these samples were investigated. Results: Seventy percent of the patients were diagnosed as the basal phenotype. Compared with the non-basal phenotype, the basal phenotype lesions were significantly larger in diameter with a high nuclear grade. In the node-negative group the basal phenotype clearly showed the same clinicopathological differences. where was significant significant concordance among all three antibodies. Conflusi on: Expression of basal markers identifies a biologically and clinically distinct subgroup of TN tumors, justifying the use of basal markers to define the basal or the non-basal phenotype. It is important to help the doctor deciding the therapeutic strategy for patient with triple- negative breast cancer.