Preoperative chemotherapy and endocrine therapy yielded low pathological complete remission (pCR) rates in patients with endocrine responsive breast cancer. Patients with large operable (cT2-T3, N0-2, M0), ER > or =10% breast cancer were treated in two consecutive studies with preoperative chemotherapy (Study I: six courses of either fluorouracil, leucovorin, vinorelbine (FLN), or vinorelbine, cisplatin, and continuous infusion of fluorouracil (ViFuP), at the discretion of the treating physician; Study II: capecitabine and oral vinorelbine (CAVINO)). Concurrent letrozole (in association with triptorelin if premenopause) was given. Sixty-five (58 evaluable) and 55 (all evaluable) patients were enrolled in the two studies. In Study I there were 43 objective responders (74%, 95% CI 63-85%), three of whom had pCR. Thirty-nine objective responses (91%) and all pCR were observed in patients with tumors expressing ER > or =50%. In Study II 34 patients (62%, 95% CI 49-75%) had an objective response. Endocrine therapy administered together with new intravenous, containing regimens should be explored in the preoperative treatment of endocrine responsive breast cancer.