Predictive Value Of HER2 Protein Expression Level In Pat Ients With HER2-positive Breast Cancer Receiving Neoadj Uvant Therapy

ObjectiveThis study aimed to detect the expression level of human epidermal growth factor receptor 2(HER-2)protein in HER-2 positive breast cancer,and to analyze the relationship between the expression level of HER-2 protein and the clinicopathological characteristics of patients with HER-2 positive breast cancer,as well as the efficacy of neoadjuvant therapy containing anti-HER2 therapy.These results provided a scientific basis for the significance of HER-2 protein expression level in predicting pathologic complete response(pCR).MethodsA total of 296 patients who received neoadjuvant chemotherapy with trastuzumab regimen in Henan Cancer Hospital from January 2014 to November2019 were retrospectively analyzed.All of the patients were assessed for clinical cancer stage Ⅱ or Ⅲ by the physical examination and imaging examination,confirmed as primary invasive breast cancer by treatment of the tubular needle biopsy breast neoplasm tissue pathology,determined the estrogen receptor,progesterone receptor,androgen receptors,HER-2,Ki67,CK5/6 and epidermal growth factor receptor status through immunohistochemical(IHC)detection technology and HER2status were all positive.All patients received 4 to 8 cycles of neoadjuvant therapy with trastuzumab,followed by mastectomy or breast-conserving surgery,axillary lymph node dissection,and postoperative pathology could be checked.The univariate comparisons of the differences in clinicopathological parameters between different HER-2 protein expression groups,and the association between HER-2 protein expression level and efficacy of neoadjuvant therapy,were made using aχ~2test or Mann–Whitney U test.Multivariate analyses of the differences in clinicopathological parameters between different HER-2 protein expression groups,and the association between HER-2 protein expression level and efficacy of neoadjuvant therapy,were performed using logistic regression analysis.ResultsA total of 110 patients achieved a pCR after neoadjuvant therapy.The pCR rate was 37.2%.The results of this study suggest that the proportion of HER-2(IHC)2+in the hormone receptor-positive group was 24.7%,which was significantly higher than that of the hormone receptor-negative group(10.0%,P=0.002).The expression level of HER-2 protein in the hormone receptor-positive group was significantly lower than that in the hormone receptor-negative group.The proportion of HER-2 2+in the androgen receptor-positive group was 17.4%,while that in the androgen receptor-negative group was 57.1%(P=0.001).The expression level of HER-2 protein in the androgen receptor-positive group was significantly higher than that in the androgen receptor-negative group,and the protein expression level of HER-2 protein in the CK5/6 positive group was significantly higher than that in the negative group(60.0%vs83.5%P=0.001).Multivariate analysis showed that HER-2 protein expression was negatively correlated with hormone receptor status(OR=0.183,P<0.001),CK5/6(OR=0.261,P=0.004),and positively correlated with androgen receptor status(OR=6.413,P=0.004).Univariate analysis showed that tumor size(P<0.001)and HER-2 protein expression level(P=0.002)were correlated with pCR rate after neoadjuvant therapy for HER-2 positive breast cancer.Multivariate analysis showed that tumor size(P=0.003)and HER-2 protein expression level were independently correlated with pCR after neoadjuvant therapy(OR=3.520,P=0.003).ConclusionsThe HER-2 protein expression level was related to multiple clinical features in patients with HER-2 positive breast cancer.For example,hormone receptor,androgen receptor,cytokeratin5/6,and HER-2 protein expression level may be used to predict the response to neoadjuvant therapy in patients with HER-2 positive breast cancer and may serve as a predictive factor for neoadjuvant therapy efficacy.