Objective  To investigate the prognostic value of estrogen receptor (ER), progesterone receptor (PR), and Ki-67 in breast cancer patients receiving neoadjuvant chemotherapy (NAC) and explore the association of chemotherapy regimens and cycles with the outcome of NAC.

  Methods  Clinical data of cancer patients receiving NAC were retrospectively analyzed. All the patients were admitted in Tianjin Medical University Cancer Institute and Hospital from January 2015 to December 2015. All statistical analyses were performed using SPSS version 19.0. The relationship among the outcome of NAC, molecular subtype, expression levels of ER, PR, and Ki-67, and chemotherapy regimens and cycles was investigated.

  Results  Only five HER-2(+) patients accepted the addition of trastuzumab in treatment, and few cases were excluded from the statistical analysis based on the effect of chemotherapy regimens. The effectiveness of NAC was positively correlated with the expression of Ki-67 whereas negatively correlated with the expression levels of ER and PR (P < 0.05). In patients receiving NAC, the patients with Luminal subtype had worse outcome than those with non-Luminal subtype (P=0.033). The invalid efficacy of pathologic evaluations of Luminal and non-Luminal NAC were 10.1% and 1.3%, respectively. No significant difference was found in the outcome among patients receiving TE, TEC, or EC-T; however, patients who received more than four cycles of NAC had better outcome than others (P=0.016). The outcome was statistically significant when the cut-off value of Ki-67 was 25%.

  Conclusion  Ki-67 proliferative index could be used as a prognostic marker to NAC in breast cancer patients. The cut-off value of Ki-67 should be determined on the basis of the data of each cancer patient. The curative effect of NAC was poor, and Luminal patients with chemotherapy were insensitive and could be considered for surgical treatment. Patients who received less than four cycles of NAC had worse outcome than others, and prompt NAC foot treatment could improve the efficiency.