Efficacy And Influence Factors Of Fulvestrant In Treatment Of Advanced Breast Cancer In Hormone Receptor-positive Women

Background:Breast cancer is the most common malignant tumor in Chinese women,and its treatment methods include surgery,chemotherapy,endocrine therapy and targeted therapy.Endocrine therapy has become the common and effective treatment way of hormone receptor-positive advanced breast cancer by blocking the estrogen pathway.Fulvestrant is a pure estrogen receptor degrader,which can selectively downgrade the level of estrogen receptor.Meanwhile it is characterized by high affinity,without partial agonist activity of estrogen like tamoxifen and low incidence of adverse events,therefor it has received a lot of attention in recent years.Studies have shown that the fulvestrant is effective in the treatment of postmenopausal hormone receptor-positive breast cancer and is well tolerated.However,the research about the clinical and pathological influence factors that affect the efficacy of the fulvestrant is still partial and controversial and needs a further discussion.Objective:To evaluate the efficacy and safety of fulvestrant for the treatment of postmenopausal patients with hormone receptor positive metastatic breast cancer.To further explore the clinical and pathological factors that affect the efficacy of fulvestrant,in order to provide theoretical basis for screening benefit population in the clinical.Method:We retrospectively analyzed the clinical data of 60 estrogen positive metastatic breast cancer patients treated with 500 mg fulvestrant in The FirstAffiliated Hospital of Dalian Medical University and The Second Affiliated Hospital of Dalian Medical University from January 1,2015-September 30,2017.Clinical efficacy,influencing factors and adverse effect were evaluated.Response Evaluation Criteria in Solid Tumors 1.1(RECIST 1.1)was used to evaluate the efficacy and the safety assessment was evaluated using the National Cancer Institute Common Toxicity Criteria 3.0(NCI-CTC 3.0).The primary endpoint was to find the progression-free survival(PFS),secondary endpoints included objective response rate(ORR)and clinical benefit rate(CBR).The Kaplan-Meier method was used for survival analysis,and Log-rank was used for testing,and Cox proportional hazard regression model was used for multivariate analysis.P<0.05 was considered statistically significant.Results:Of the 60 patients receiving treatment of 500 mg of fulvestrant,median age was 52(29~80)years,median treatment cycle is 5(2~16),median progression free survival(PFS)was 6.0 months(95%CI:5.0~7.5 months).There were no complete response(CR)take place in the whole group.3 cases occurred progressive disease(PR,3/60,5%),44 cases occurred stable disease(SD,44/60,73.3%),among them,32 patients who achieved stable disease granter than 24 weeks.13 cases occurred partial response(PD,13/60,21.7%).objective response rate(CR+PR)was5%(3/60),clinical benefit rate(CR+PR+SD≥24 weeks)was 58.3%(35/60).Single factor analysis showed that after the treatment of 500 mg fulvestrant,there was no significant correlation between PFS with age,the way of menopause,status of PR,clinical stage was IV in primary treatment,the number of metastatic lesions,visceral metastasis,bone metastasis alone,treated by radical operation,treated by adjuvant chemotherapy and endocrine resistance(P>0.05),but significantly correlated with chemotherapy therapy after metastasis(x2=6.645,P=0.01),prior aromatase inhibitors use(x2=10.434,P=0.005),and the dose of fulvestrant(x2=13.549,P=0.001).COX proportional hazard regression analysis indicated that PFS was prolonged in patients who were not received the treatment of aromatase inhibitors or just accepted aromatase inhibitors for adjuvant therapy have a longer PFS than those who hadreceived the treatment of aromatase inhibitors after advanced(HR=0.516;95%CI:0.3~1.0;P=0.033),and the more earlier the fulvestrant was used,the longer PFS the patients had(HR=1.646;95%CI:1.0~2.7;P=0.047).After treated with fulvestrant,the main adverse events were injection site reaction,loss of appetite,nausea and fatigue,the incidence of adverse symptoms were I grade and there were no II and higher grade adverse symptoms happened.No treatment-related death occurred.Conclusion:1、The fulvestrant has a favorable efficacy and safety in treatment of advanced breast cancer in hormone receptor-positive postmenopausal women.2、Especially for the patients who had not used aromatase inhibitors before or just used it for adjuvant therapy,the earlier the fulvestrant used,the better the efficacy.3、The overall security is well.