OBJECTIVETo assess the effect of neoadjuvant chemotherapy and the factors related with pathological complete response (pCR) of neoadjuvant chemotherapy in breast cancer.

METHODSThe data of 159 primary breast cancer patients who had received neoadjuvant chemotherapy and operation with complete MRI data and histopathology evaluation in this center from January 2009 to December 2011 was analyzed. All the patients were female, aging from 28 to 70 years with a median of 50 years. The neoadjuvant chemotherapy regimens were based on anthracyclines or taxanes, and trastuzumab was used in almost half of the human epidermalgrowth factor receptor 2 positive patients. The response of neoadjuvant chemotherapy was comprehensively evaluated based on RECIST 1.1 and Miller-Payne grading system. SPSS 18.0 was used for statistical analysis.

RESULTSAmong the 159 patients, 10.1% patients had achieved complete response according to the MRI evaluation, and the rate of partial response, stable disease, and progressive disease was 65.4%, 24.5%, and 0 respectively. According to the Miller-Payne grading system, 27.7% patients had pathological response evaluated as G5 (pCR), and the response evaluated as G4, G3, G2, and G1 were 28.3%, 18.9%, 12.6%, and 12.6% respectively. The higher histological grade were correlated with pCR statistically (Z = -2.820, P = 0.005). Meanwhile strong expression of Ki67 (Z = -1.989, P = 0.047) and p53 (Z = -2.457, P = 0.014) were related to pCR in a significant statistically way.

CONCLUSIONSThe response of neoadjuvant chemotherapy can be predicted. The histological grade and the immunohistochemistry results of Ki67 and p53 are related to pCR of neoadjuvant chemotherapy for primary breast cancer. Basal-like breast cancer had a higher pCR statistically.