Background:Extensive studies have confirmed the efficacy of taxanes in combination with anthracycline-based chemotherapy on breast cancer.However,few studies have assessed the efficacy of weekly taxane-anthracycline regimens on locally advanced breast cancer.This study was to compare the efficacy and safety of a weekly taxaneanthracycline regimen with those of tri-weekly anthracycline-based regimen in patients with locally advanced breast cancer.Methods:Patients with locally advanced breast cancer were randomized to receive 4-6 cycles of neoadjuvant chemotherapy with tri-weekly 5-fluorouracil-epirubicin-cyclophosphamide(FEC) regimen or weekly paclitaxel-epirubicin(PE) regimen.The primary endpoint was the pathologic complete response(pCR) rate.Other endpoints included the clinical tumor response,breast-conserving surgery rate,and adverse events.Results:Between March 2010 and September 2013,293 patients were randomized to the FEC(n=151) and PE(n=142) arms.The overall clinical response rate was significantly higher in the PE arm than in the FEC arm(76.06%vs.59.95%,P=0.001).Consistently,the post-chemotherapy pathologic T and N stages were significantly lower in the PE arm than in the FEC arm(P<0.001).However,the pCR rate was similar in the two arms(10.61%vs.12.31%,P=0.665).Overall,36(27.27%) patients in the FEC arm and 6(35.28%) in the PE arm were qualified for breast-conserving surgery.Most adverse events were comparable in both arms,with more severe neutropenia in the PE arm than in the FEC arm(11.97%vs.5.96%,P=0.031).Conclusions:In patients with locally advanced breast cancer,weekly PE was not superior to FEC in terms of pCR.However,weekly PE has a higher response rate and superior down-staging effects.On this account,the PE regimen may be considered an alternative option for locally advanced breast cancer.Long-term follow-up data are needed to confirm the efficacy of this regimen on locally advanced breast cancer.Trial registration Chinese clinical trial registry,ChiCTR-TRC-10001043,September 21,2014 Background: Extensive studies have confirmed the efficacy of taxanes in combination with anthracycline-based chemotherapy on breast cancer. However, few studies have assessed the efficacy of weekly taxane-anthracycline regimens on locally advanced breast cancer. This study was to compare the efficacy and safety of a weekly taxaneanthracycline regimen with those of tri-weekly anthracycline-based regimen in patients with locally advanced breast cancer. Methods: Patients with locally advanced breast cancer were randomized to receive 4-6 cycles of neoadjuvant chemotherapy with tri-weekly 5-fluorouracil- epirubicin-cyclophosphamide (FEC) regimen or weekly paclitaxel-epirubicin (PE) regimen. The primary endpoint was the pathologic complete response (pCR) rate.Other endpoints included the clinical tumor response, breast-conserving surgery rate, and adverse events. Results: Between March 2010 and September 2013,293 patients were randomized to the FEC (n = 151) and PE (n = 142) arms. The overall clinical response ra ra The post-chemotherapy pathologic T and N stages were significantly lower in the PE arm than in the FEC arm (76.06% vs. 59.95%, P = 0.001) P <0.001). Although the pCR rate was similar in the two arms (10.61% vs. 12.31%, P = 0.665), Overall, 36 (27.27%) patients in the FEC arm and 6 (35.28%) in the PE arm were qualified for breast-conserving surgery. Host adverse events were comparable in both arms, with more severe neutropenia in the PE arm than in the FEC arm (11.97% vs 5.96%, P = 0.031) .Conclusions: In patients with locally advanced breast cancer, weekly PE was not superior to FEC in terms of pCR. Yetever, weekly PE has a higher response rate and superior down-staging effects. Of this account, the PE regimen may be considered an alternative option for locally advanced breast cancer .Long-term follow-up data are needed to confirm the efficacy of this regimen on locally advanced breast cancer. Serial registration Chinese clinical trial registry, ChiCTR-TRC-10001043, September 21,2014