Individualized treatment of breast cancer has become one of the main directions in the clinical and research areas of breast cancer,and the individualized treatment of the estrogen receptor(ER) positive patients which covered 65% of total cases is of vital importance. Historical research showed that among the ER-positive and HER2-negative breast cancer,Luminal B breast cancer with Ki67\>14% is more likely to be benefited from chemotherapy,compared with the Luminal A breast cancer with Ki67\<14%. And the results of our previous research showed that, the neoadjuvant XT protocol has more than 17% pCR rate in Luminal B subtype breast cancer.However,to those who didn't reach pCR,we've got no evidence whether switching to Anthracycline-based post operative protocol can benefit them.So that,we sketch out a randomized controlled multicentric phase III clinical trail.HER2 negative Luminal B subtype breast cancer patients are included. After 4 cycles of XT protocol neoadjuvant chemotherapy ,those who reach PR but not pCR are randomly divided into the group treated with XT protocol and the group with XEC protocol ,then compare the DFS and OS of two subgroup.
