Objective: To investigate the efficacy and safety of neoadjuvant chemotherapy with epirubicin plus paclitaxel (E+T) in patients undergoing breast conserving surgery for breast cancer. 
Methods: One-hundred and seven female patients with 107 patients with stage IIa-IIIa primary breast cancer admitted from January 2014 to January 2018 were enrolled. All patients received 3-week E+T neoadjuvant chemotherapy before breast-conserving surgery, and all patients underwent detection of the expressions of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), Ki-67, p53 and Bcl-2 in the hollow needle aspiration specimens before neoadjuvant chemotherapy. The clinical and pathological outcomes were assessed, and the toxic and adverse effects were evaluated.
Results: All patients completed 4 or 6 courses of 3-week E+T neoadjuvant chemotherapy before operation, and the tumor stage was downgraded to stage IIb in 5 stage IIIa patients after chemotherapy. All patients underwent breast-conserving surgery 12-16 d after neoadjuvant chemotherapy. The clinical effective rate was 89.72%, the pathological complete response (pCR) rate was 17.76%, and the negative conversion rate of the axillary lymph nodes (ALN) was 54.76%. There were significant differences in pCR rates between patients with positive and negative expressions of ER, PR, Ki-67 and p53 (all P<0.05), but no significant differences in pCR rates between patients with positive and negative expressions of HER-2 and Bcl-2 (both P>0.05). All toxic effects were tolerable, except for degree IV leukopenia in 5 cases and degree IV neutropenia in 5 cases. Eighty-six patients were followed up for 12-60 months, recurrence and metastasis occurred in 19 cases, death occurred in 6 cases, and contralateral breast cancer occurred in 2 cases, while the remaining patients recovered well.
Conclusion: In breast cancer patients undergoing breast-conserving surgery, higher pCR rate can achieved by neoadjuvant chemotherapy of E+T regimen with tolerable toxic and adverse reactions. ER, PR, Ki-67, p53 can be used as efficacy predictors for E+T neoadjuvant chemotherapy.