RESUMEN
In the randomized phase 2 study there was evaluated the efficacy of neoadjuvant endocrine treatment (anastrozole, exemestane) in comparison with chemotherapy (doxorubicin plus paclitaxel). Preoperative endocrine therapy was well tolerated. There was a trend towards higher overall rates of objective response and breast conserving surgery (BCS) among patients with tumors expressing high levels of ER (luminal A) in endocrine therapy group compared with chemotherapy group (43% vs 24%; p = 0,054). In HER2-positive breast cancer patients the addition of trastuzumab to neoadjuvant chemotherapy improved the overall and pathological complete response. Trastuzumab made possible an increasing number of breast conserving surgery (23% vs 13%; p = 0,022). No patient treated with trastuzumab and with chemotherapy had a local recurrence after BCS.