Ki-67 Change in Anthracyline-containing Neoadjuvant Chemotherapy Response in Breast Cancer

Objective Anthracycline-containing regimens are irreplaceable in neoadjuvant chemotherapy(NAC)for breast cancer(BC)at present.However,30% of early breast cancer(EBC)patients are resistant to anthracycline-containing chemotherapy,leading to poor prognosis and higher mortality.Ki-67 is associated with the prognosis and response to therapy,and it changes after NAC.Methods A total of 105 BC patients who received anthracycline-containing NAC were enrolled.Then,the optimal model of Ki-67 was selected,and its predictive efficacy was analyzed.Immunohistochemistry(IHC)was used to determine the estrogen receptor(ER),progesterone receptor(PR),and human epidermal growth factor receptor 2(HER-2)status and Ki-67 level.Fluorescent in situ hybridization(FISH)was used to verify the HER-2 when the IHC score was 2+.Results The post-NAC Ki67 level after treatment with anthracycline drugs was lower than pre-NAC Ki-67(19.6%±23.3%vs.45.6%±23.1%,P<0.001).Furthermore,patients with the Ki-67 decrease had a border line higher pathological complete response(pCR)rate(17.2%vs.0.0%,P=0.068),and a higher overall response rate(ORR)(73.6%vs.27.8%,P<0.001),when compared to patients without the Ki-67 decrease.The ΔKi-67 and ΔKi-67%were valuable markers for the prediction of both the pCR rate and ORR.The area under the curve(AUC)for ΔKi-67 on pCR and ORR was 0.809(0.698-0.921)and 0.755(0.655-0.855),respectively,while the AUC for ΔKi-67% on pCR and ORR was 0.857(0.742-0.972)and 0.720(0.618-0.822),respectively.Multivariate logistic regression model 1 revealed thatΔKi-67 was an independent predictor for both pCR[odds ratio(OR)=61.030,95% confidence interval(CI)=4.709-790.965;P=0.002]and ORR(OR=10.001,95%CI:3.044-32.858;P<0.001).Multivariate logistic regression model 2 revealed thatΔKi-67%was also an independent predictor for both pCR(OR=408.922,95%CI=8.908-18771.224;P=0.002)and ORR(OR=5.419,95%CI=1.842-15.943;P=0.002).Conclusions The present study results suggest thatΔKi67 andΔKi67%are candidate predictors for anthracycline-containing NAC response,and that they may provide various information for further systematic therapy after surgery in clinical practice.