Effect Of Adjuvant Endocrine Therapy In Breast Cancer Patients With A Positive-to-negative Switch Of Hormone Receptor Status After Neoadjuvant Chemotherapy

Background:Breast cancer is a common malignant tumor in women.According to the statistics published by the WHO,breast cancer has risen to a global female primary malignant tumor.The results of the study of NSABP B-18 confirmed the significance of neoadjuvant chemotherapy in the treatment of locally advanced breast cancer.Neoadjuvant chemotherapy has been widely used in the field of breast cancer,and has become one of the standard treatment models for locally advanced breast cancer.Breast cancer is a hormone-dependent tumor,and its development is closely related to the expression of hormone receptor.Estrogen receptor(ER)and progesterone receptor(PR)are important clinical indicators in the treatment and prognosis of breast cancer.Studies have reported that in the neoadjuvant chemotherapy process,some patients will have changes in ER and PR status,but only a small amount of studies indicates whether patients with hormone receptor positive to negative alter after neoadjuvant chemotherapy can benefit from adjuvant endocrine therapy.Therefore,this study demonstrated the effect of neoadjuvant chemotherapy on the changes of hormone receptor and the prognosis of patients with breast cancer after neoadjuvant chemotherapy with endocrine therapy.Objective:To explore the effect of adjuvant endocrine therapy(AET)in breast cancer patients with a positive-to-negative switch of hormone receptor(HR)status after neoadjuvant chemotherapy(NAC).Methods:One hundred and six patients who presented with hormone receptor(HR)-positive breast cancer at diagnosis and turned to HR-negative after NAC from December 2000 to December 2013 in Jiaxing Maternity and Child Care Hospital were retrospectively identified.According to whether adopted adjuvant endocrine divided into observation group and control group.Kaplan-Meier analysis and log-rank test were used for univariate analysis of factors predictive of disease-free survival(DFS)and overall survival(OS).Multivariate analysis was carried out using the Cox proportional hazards model in patients with DFS and OS.Results:All the patients were categorized into two groups on the basis of the administration of AET:61 AET-administered patients(57.5%)and 45 AET-naive patients(42.5%).After a median follow-up of 68 months(range 14～103months),human epidermal growth factor receptor 2(HER-2)status,initial clinical stage,pathological axillary lymph node status and the use of AET were identified as the independent predictors for the DFS and OS(all P<0.05.Patients treated with AET had a significantly improved 5-year DFS rate when compared with those without AET(77.1%vs 53.5%,P<0.05).The 5-year OS of AET-administered patients was also better than that of AET-naive patients(80.9%vs 71.0%,P<0.05).Cox regression analysis showed that AET-administered or not was the independent predictor for 5-year DFS(HR=2.096,95%CI:1.081～4.065,P<0.05),but 5-year OS has no significant difference(HR=1.927,95%CI:0.0921～4.115,P>0.05).Conclusion:Test of HR status of breast cancer before NAC is prerequisite for selection of optimal therapy.Because NAC may change HR status,test the HR status is still needed after surgey.Patients with HR altered from positive to negative after NAC still gain benefit from AET.