Clinicopathological Features and Long-Term Prognostic Role of Human Epidermal Growth Factor Receptor-2 Low Expression in Chinese Patients with Early Breast Cancer:A Single-Institution Study

Objective This study aimed to comprehensively analyze and compare the clinicopathological features and prognosis of Chinese patients with human epidermal growth factor receptor 2(HER2)-low early breast cancer(BC)and HER2-IHC0 BC.Methods Patients diagnosed with HER2-negative BC(N=999)at our institution between January2011 and December 2015 formed our study population.Clinicopathological characteristics,association between estrogen receptor(ER)expression and HER2-low,and evolution of HER2 immunohistochemical(IHC)score were assessed.Kaplan-Meier method and log-rank test were used to compare the long-term survival outcomes(5-year follow-up)between the HER2-IHC0 and HER2-low groups.Results HER2-low BC group tended to demonstrate high expression of ER and more progesterone receptor(PgR)positivity than HER2-IHC0 BC group(P<0.001).The rate of HER2-low status increased with increasing ER expression levels(Mantel-Haenszelχ^(2)test,P<0.001,Pearson’s R=0.159,P<0.001).Survival analysis revealed a significantly longer overall survival(OS)in HER2-low BC group than in HER2-IHC0 group(P=0.007)in the whole cohort and the hormone receptor(HR)-negative group.There were no significant differences between the two groups in terms of disease-free survival(DFS).The discordance rate of HER2 IHC scores between primary and metastatic sites was 36.84%.Conclusion HER2-low BC may not be regarded as a unique BC group in this population-based study due to similar clinicopathological features and prognostic roles.

Tumor biology in estrogen receptor-positive,human epidermal growth factor receptor type 2-negative breast cancer:Mind the menopausal status

Breast cancer is not one disease,but can be categorized into four major molecular subtypes according to hormone receptor [estrogen receptor(ER) and progesterone receptor(Pg R)] and human epidermal growth factor receptor type 2(HER2) expression status. Ki67 labeling index and/or multigene assays are used to classify ERpositive,HER2-negative breast cancer into luminal A and luminal B(HER2-negative) subtypes. To date,most studies analyzing predictive or prognostic factors in ER-positive breast cancer have been performed in postmenopausal women,mainly using patients and samples in adjuvant aromatase inhibitor trials. In contrast,even the clinical roles of Pg R and Ki67 have been little analyzed so far in premenopausal women. Pg R is one of the estrogen-responsive genes,and it has been reported that plasma estradiol levels are related to expression levels of estrogen-responsive genes including PGR in ER-positive breast cancer. In this article,biological differences,especially differences in expression of Pg R and Ki67 in ER-positive breast cancer between pre- and postmenopausal women are discussed. Clinical roles of Pg R and Ki67 in ER-positive breast cancer differ between pre- and postmenopausal women. We suggest that the mechanisms of development and estrogen-dependent growth of ER-positive breast cancer might differ according to menopausal status.

LACKING EXON5 OF VARIANT ESTROGEN RECEPTOR IN HUMAN BREAST CANCER

Methods: The target sequence of ER RNA covering exon4(6(1082(1520bp) was amplified in 7 clinical human breast cancer tissues by reverse transcription and polymerase chain reaction (RTPCR) techniques. Results: PCR products were transferred to nitrocellulose membranes and hybridized using a [r32P]ATP labeled ER 29 oligonulceotide probe representing the antisense strand of the ER Cdna sequence 1271(1299. Specific bands were found at 438 and 300 base pairs in two tumors. The 300 base pair of PCR product was recovered from ER+/PR+ and ER+/PR tumor, respectively. Conclusion: Dideoxy sequence analysis revealed that they contained the variant ER completely missing exon 5.

Current medical treatment of estrogen receptor-positive breast cancer

Approximately 80% of breast cancers(BC) are estrogen receptor(ER)-positive and thus endocrine therapy(ET) should be considered complementary to surgery in the majority of patients. The advantages of oophorectomy, adrenalectomy and hypophysectomy in women with advanced BC have been demonstrated many years ago, and currently ET consist of(1) ovarian function suppression(OFS), usually obtained using gonadotropinreleasing hormone agonists(Gn RHa);(2) selective estrogen receptor modulators or down-regulators(SERMs or SERDs); and(3) aromatase inhibitors(AIs), or a combination of two or more drugs. For patients aged less than 50 years and ER+ BC, there is no conclusive evidence that the combination of OFS and SERMs(i.e., tamoxifen) or chemotherapy is superior to OFS alone. Tamoxifen users exhibit a reduced risk of BC, both invasive and in situ, especially during the first 5 years of therapy, and extending the treatment to 10 years further reduced the risk of recurrences. SERDs(i.e., fulvestrant) are especially useful in the neoadjuvant treatment of advanced BC, alone or in combination with either cytotoxic agents or AIs. There are two types of AIs: type Ⅰ are permanent steroidal inhibitors of aromatase, while type Ⅱ are reversible nonsteroidal inhibitors. Several studies demonstrated the superiority of the third-generation AIs(i.e., anastrozole and letrozole) compared with tamoxifen, and adjuvant therapy with AIs reduces the recurrence risk especially in patients with advanced BC. Unfortunately, some cancers are or became ET-resistant, and thus other drugs have been suggested in combination with SERMs or AIs, including cyclin-dependent kinase 4/6 inhibitors(palbociclib) and mammalian target of rapamycin(m TOR) inhibitors, such as everolimus. Further studies are required to confirm their real usefulness.

Evaluation of human epidermal growth factor receptor 2 status of breast cancer using preoperative multidetector computed tomography with deep learning and handcrafted radiomics features

Objective:To evaluate the human epidermal growth factor receptor 2(HER2)status in patients with breast cancer using multidetector computed tomography(MDCT)-based handcrafted and deep radiomics features.Methods:This retrospective study enrolled 339 female patients(primary cohort,n=177;validation cohort,n=162)with pathologically confirmed invasive breast cancer.Handcrafted and deep radiomics features were extracted from the MDCT images during the arterial phase.After the feature selection procedures,handcrafted and deep radiomics signatures and the combined model were built using multivariate logistic regression analysis.Performance was assessed by measures of discrimination,calibration,and clinical usefulness in the primary cohort and validated in the validation cohort.Results:The handcrafted radiomics signature had a discriminative ability with a C-index of 0.739[95%confidence interval(95%CI):0.661-0.818]in the primary cohort and 0.695(95%CI:0.609-0.781)in the validation cohort.The deep radiomics signature also had a discriminative ability with a C-index of 0.760(95%CI:0.690-0.831)in the primary cohort and 0.777(95%CI:0.696-0.857)in the validation cohort.The combined model,which incorporated both the handcrafted and deep radiomics signatures,showed good discriminative ability with a C-index of 0.829(95%CI:0.767-0.890)in the primary cohort and 0.809(95%CI:0.740-0.879)in the validation cohort.Conclusions:Handcrafted and deep radiomics features from MDCT images were associated with HER2 status in patients with breast cancer.Thus,these features could provide complementary aid for the radiological evaluation of HER2 status in breast cancer.

Polyubiquitination inhibition of estrogen receptor alpha and its implications in breast cancer

Estrogen receptor alpha(ERα) is detected in more than 70% of the cases of breast cancer. Nuclear activity of ERα, a transcriptional regulator, is linked to the development of mammary tumors, whereas the extranuclear activity of ERα is related to endocrine therapy resistance. ERα polyubiquitination is induced by the estradiol hormone, and also by selective estrogen receptor degraders, resulting in ERα degradation via the ubiquitin proteasome system. Moreover, polyubiquitination is related to the ERα transcription cycle, and some E3-ubiquitin ligases also function as coactivators for ERα. Several studies have demonstrated that ERα polyubiquitination is inhibited by multiple mechanisms that include posttranslational modifica-tions, intera-ctions with coregula-tors, a-nd forma-tion of specific protein complexes with ERα. These events are responsible for an increase in ERα protein levels and deregulation of its signaling in breast cancers. Thus, ERα polyubiquitination inhibition may be a key factor in the progression of breast cancer and resistance to endocrine therapy.

Estrogen receptor alpha gene amplification in breast cancer:25 years of debate

Twenty-five years ago,Nembrot and colleagues reported amplification of the estrogen receptor alpha gene(ESR1) in breast cancer,initiating a broad and still ongoing scientific debate on the prevalence and clinical significance of this genetic aberration,which affects one of the most important genes in breast cancer.Since then,a multitude of studies on this topic has been published,covering a wide range of divergent results and arguments.The reported prevalence of this alteration in breast cancer ranges from 0% to 75%,suggesting that ESR1 copy number analysis is hampered by technical and interpreter issues.To date,two major issues related to ESR1 amplification remain to be conclusively addressed:(1) The extent to which abundant amounts of messenger RNA can mimic amplification in standard fluorescence in situ hybridization assays in the analysis of strongly expressed genes like ESR1,and(2) the clinical relevance of ESR1 amplification:Such relevance is strongly disputed,with data showing predictive value for response as well as for resistance of the cancer to anti-estrogen therapies,or for subsequent development of cancers in the case of precursor lesions that display amplification of ESR1.This review provides a comprehensive summary of the various views on ESR1 amplification,and highlights explanations for the contradictions and conflicting data that could inform future ESR1 research.

Loss of the vitamin D receptor in human breast and prostate cancers strongly induces cell apoptosis through downregulation of Wnt/β-catenin signaling

Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihydroxy-vitamin D [1,25（OH）2D] are mediated through binding to the vitamin D receptor （VDR）. Here, we report on the unexpected finding that stable knockdown of VDR expression in the human breast and prostate cancer cell lines, MDA-MB-231 and PC3, strongly induces cell apoptosis and inhibits cell proliferation in vitro. Implantation of these VDR knockdown cells into the mammary fat pad （MDA-MB-231）, subcutaneously （PC3） or intra-tibially （both cell lines） in immune-incompetent nude mice resulted in reduced tumor growth associated with increased apoptosis and reduced cell proliferation compared with controls. These growth-retarding effects of VDR knockdown occur in the presence and absence of vitamin D and are independent of whether cells were grown in bone or soft tissues. Transcriptome analysis of VDR knockdown and non-target control cell lines demonstrated that loss of the VDR was associated with significant attenuation in the Wnt/0-catenin signaling pathway. In particular, cytoplasmic and nuclear β-catenin protein levels were reduced with a corresponding downregulation of downstream genes such as Axin2, Cyclin D1, interleukin-6 （IL-6）, and IL-8. Stabilization of 0-catenin using the GSK-3β inhibitor BIO partly reversed the growth-retarding effects of VDR knockdown. Our results indicate that the unliganded VDR possesses hitherto unknown functions to promote breast and prostate cancer growth, which appear to be operational not only within but also outside the bone environment. These novel functions contrast with the known anti-proliferative nuclear actions of the liganded VDR and may represent targets for new diagnostic and therapeutic approaches in breast and prostate cancer.

Expression of ΔDNMT3B Variants and Its Association with Estrogen/Progestogen Receptor Status in Breast Cancer

Objective： Our previous study has showed that △DNMT3B is the predominant form of DNMT3B in non-small cell lung cancer （NSCLC）. In this study, we aimed to explore the expression patterns of the △DNMT3B variants in breast cancer and to identify whether the pattern was similar to that in NSCLC or not and its clinical significance. Methods： Expression of seven △DNMT3B variants in 59 breast cancer and the corresponding normal tissue was measured using RT-PCR. The correlations between the expressions of △DNMT3B variants and the clinical parameters including ER/PR status, clincopathologic feature and survivals were analyzed. Results： There were significant differences in the expression ratios of △DNMT3B1-7 variants between breast cancer tissues and normal tissues （P〈0.001）. The positive ratio of △DNMT3B1-7 variants were 66%, 71%, 17%, 51%, 76.2%, 50% and 61% in tumor tissue, respectively; while 16%, 8.4%, 3.38%, 3.38%, 11.8%, 13.5% and 5.08% in the corresponding normal tissue, which was different from the pattern of △DNMT3B1-7 expression in NSCLC （62%, 76%, 2.5%, 46%, 18%, 27% and 16% in tumor tissue, respectively; while 18%, 11%, 0%, 3.3%, 0%, 0% and 0% in normal lung tissue, respectively; P〈0.0001）. Expressions of △DNMT3B2, 3B4 and 3B7 were higher in the patients with negative estrogen receptor （ER） than those with positive estrogen receptor （P=0.035, P=0.0141 and P=0.0219, respectively）. △DNMT3B7 expression was higher for the patients with negative progestogen receptor （PR） compared to those with positive progestogen receptor （P=0.0379）. Expression ratio of △DNMT3B5 in stage Ⅲ tumors is lower than that in stage Ⅰ/Ⅱ ones （P= 0.041）. But we did not find any relation between the △DNMT3B variants and the patients＇ survival. Conclusion： The pattern of △DNMT3B variants in breast cancer is different from that in NSCLC. Expressions of △DNMT3B2, 3B4 and 3B7 are associated with estrogen receptors status. While △DNMT3B7 is associated with progestogen receptor. No relation between the △DNMT3B variants and the patients＇ survival were found.

Correlation of Hormonal Receptors Estrogen Receptor, Progesterone Receptor and Her-2/Neu with Tumor Characteristics in Breast Carcinoma: Study of 100 Consecutive Cases

Introduction-Breast cancer is the most common cancer and leading cause of death in women. In India, its incidence is rapidly rising over last few decades. Present study is aimed to study the pattern of expression of hormonal receptors and Her-2/neu in invasive breast carcinoma and to correlate estrogen receptor (ER), progesterone receptor (PR) and Her-2/neu expressions with various clinicopathological parameters. Material and methods: The present study was carried out in Department of Pathology, S.C.B. Medical College, Cuttack in the year 2013 taking consecutive 100 cases. Routine H&E staining for histological diagnosis and IHC analysis for ER, PR and Her 2/neu was carried out in all 100 cases of breast malignancies. Results: 99% of cases are invasive breast carcinoma, not otherwise specify (IDC-NOS). The age ranges from 23 years to 72 years. Majority of tumors are of grade 2 (70%) followed by grade 3 (30%). ER PR and Her-2/neu expression are seen in 45%, 35% and 30% respectively. Triple negative cases comprise 35%. Higher number of grade 2 tumor shows ER, PR positivity as compared to grade 3 tumors. Her-2/neu expression does not show any significant correlation with age or lymph node status of the patient. Conclusion: ER and PR expression in breast cancers in the current study are found to be comparable to the findings of other authors, but the frequency of HER-2/neu expression is slightly higher. Significant correlation is observed between hormonal receptor status and the grade of the tumor. Inverse relationship is found between Her-2/neu expression and ER, PR receptor status. Her-2/neu expression is increased with size and high grade of tumor.

Increased Cellular Invasion and Proliferation via Estrogen Receptor after 17-<i>β</i>-Estradiol Treatment in Breast Cancer Cells Using Stable Isotopic Labeling with Amino Acids in Cell Culture (SILAC)

17-β-estradiol (estrogen) is a steroid hormone important to human development;however, high levels of this molecule are associated with increased risk of breast cancer primarily due to estrogen’s ability to bind and activate the estrogen receptor (ER) and initiate gene transcription. Currently, estrogen mechanisms of action are classified as genomic and non-genomic and occur in an ER-dependent and ER-independent manner. In this study, we examine estrogen signaling pathways, by measuring changes in protein expression as a function of time of exposure to estrogen in both ER-positive (MCF-7) and ER-negative (MDA-MB-231) cell lines. Using a robust experimental design utilizing isotopic labeling, two-dimensional LC-MS, and bioinformatics analysis, we report genomic and non-genomic ER regulated estrogen responsive proteins. We find a little over 200 proteins differentially expressed after estrogen treatment. Cell proliferation, transcription, actin filament capping and cell to cell signaling are significantly enriched in the MCF-7 cell line alone. Translational elongation and proteolysis are enriched in both cell lines. Subsets of the proteins presented in this study are for the first time directly associated with estrogen signaling in mammary carcinoma cells. We find that estrogen affected the expression of proteins involved in numerous processes that are related to tumorigenesis such as increased cellular division and invasion in an ER-dependent manner. Moreover, we identified negative regulation of apoptosis as a non-genomic process of estrogen. This study complements gene expression studies and highlights the need for both genomic and proteomic analyses in unraveling the complex mechanisms by which estrogen affects progression of breast cancer.

A Review Study on the Effects of Estrogen Level on Vaginal Candida spp.of Women with Estrogen-Related Receptor Breast Cancer

The aim of the present study have been reported to review the estrogen level in the patients with the breast cancer and healthy individuals.Breast cancer is one of the most common diseases in women worldwide that is characterized by uncontrolled growth of malignant cells in the mammary epithelial tissue.The estrogen was found at normal level in most patients with ER-positive breast cancer and in healthy individuals,while its high level was higher among patients with ER-negative breast cancer.Many studies show evidences about the role of estrogen at a high level on the development of breast cancer.The association between the estrogen levels and the presence of Candida spp.in vagina of patients with breast cancer was reviewed.

ESTROGEN RECEPTOR-NEGATIVE BREAST CANCER CELLS TRANSFECTED WITH ESTROGEN RECEPTOR EXHIBIT DECREASED TUMOUR PROGRESSION AND SENSITIVITY TO GROWTH INHIBITION BY ESTROGEN

Breast cancer containing estrogen receptors (ER ) are responslve to antiestrogen treatment and have a better prognosis compared with ER-negative tumors. The loss of estrogen receptors appears to be associated with a progression to less clifferentiated cells. We transfected the human ER into the ER-negative breast cancer cell line MDA MD 231 cells. We found that expresslon of adequate ER is strong associated with the ability of human breast cancer cell growth inhibition and progression. Compared with nontransfected or mock-trans fected cells, ER-transfected cells exhibited growth slower, forming smaller colonles in soft agar and growth inhibited by estrogen and tamoxifen. Therefore reactivation or transfection of the estrogen receptor gene can be considered as therapeutic approaches to hormone-independent breast cancer.

Correlation of estrogen and progesterone receptors ER and PR expression with the growth of endometrial cancer

Objective:To study the correlation of estrogen and progesterone receptors ER and PR expression with the growth of endometrial cancer.Methods: A total of 80 patients with endometrial cancer who were treated collected in the Fourth People's Hospital of Shaanxi and the First Affiliated Hospital of Xi'an Jiaotong University between January 2013 and January 2017 were collected, endometrial cancer tissue and para-carcinoma normal tissue were collected, immunohistochemical method was used to detect positive expression of ER and PR, and fluorescence quantitative PCR was used to detect the mRNA expression of proliferation and apoptosis genes.Results: The positive expression of ER and PR in tumor tissue were significantly lower than those in para-carcinoma tissue;proliferation genes KCC1, RRM2, SRPX2 and Snail mRNA expression in tumor tissue of ER-positive group and PR-positive group were lower than those of ER-negative group and PR-negative group;anti-apoptosis genes Wip-1 and Bcl-2 mRNA expression were lower than those of ER-negative group and PR-negative group respectively while pro-apoptosis genes Bid, Bax and Fas mRNA expression were higher than those of ER-negative group and PR-negative group respectively.Conclusion:Patients with positive expression of endometrial estrogen and progesterone receptors ER and PR are with lower tumor proliferation activity, higher apoptosis activity and lower malignant degree than patients with negative ER and PR expression.

The Relationship of CyclinD1 and Estrogen Receptor Expression in the Process of Proliferation and Metastasis in Breast Neoplasm

The role of CyclinD1 and estrogen receptor (ER) in the process of proliferation and metastasis of breast neoplasm and their relationship were studied. The expression levels of CyclinD1 and ER in the tissue samples were detected by using flow cytometry and L SAB immunohistochemistry staining, respectively. The results showed that CyclinD1 and ER expression levels in breast cancer were significantly higher than in benign breast neoplasm (P<0.05). The CyclinD1 expression levels in stage I was much lower than in stages Ⅱ, Ⅲ, Ⅳ (P<0.05). The positive rate of ER was not related with tumor size, lymph node metastasis and TNM stage (P>0.05), but the CyclinD1 expression level in ER (+) group was significantly higher than in ER (-) group (P<0.05). It was concluded that CyclinD1 expression level might be obviously related with the proliferation and metastasis of breast neoplasm and ER.

Relationship between sex hormone receptors and ultrastructural cellular differentiation in breast cancer:an observation in 40 patients

Estrogen and progesterone receptor (ER and PR) contents of 40 breastcancer patients were determined with immunofluorescent staining.Thedifferentiation of cancer cells was evaluated on the basis of histological andultrastructural changes.It was found that there was a positive correlation of ERand PR contents with the cellular differentiation of breast cancer,and the lattercould be used to estimate the status of hormone receptors.Breast cancer is a malignant disease with heteropathological characteristics.In handling a breast cancerpatient,both the status of hormone receptors and the cellular differentiationshould be considered and the treatment varied with each pa(?)ent.For those witha well-differentiated cancer and rich hormone receptors,endocrine therapy shouldmainly be administered,while for those with a poorly-differentiated cancer and afew hormone receptors,chemotherapy would be of choice.

Level of Adherence to Breast Cancer Molecular Subtyping among Women with Breast Cancer Attending Tertiary Health Facilities

Background: Breast cancer is a genetically and clinically heterogeneous disease with multiple subtypes. The classification of these subtypes has evolved over the years. The most common and widely accepted classification of breast cancer is from an immunohistochemical perspective, based on the expression of the following hormone receptors: Estrogen Receptor (ER), Progesterone Receptor (PR) and Human Epidermal Growth Factor (HER2). Accordingly, the following four subtypes of breast cancer are widely recognized—Luminal A, Luminal B, HER2 Enriched and Triple Negative. Breast cancer management approaches include surgery, chemotherapy, radiotherapy and targeted hormone therapy necessitated by molecular subtyping. Aims: This study aimed to determine the level of adherence to breast cancer molecular subtyping among women with breast cancer attending tertiary health facilities in Imo State. Methodology: Immunohistochemistry reports of women with breast cancer attending tertiary health facilities in Imo State were retrieved from patient’s case files. Tissue blocks were also retrieved from tissue block archives of both hospitals for women who did not take up immunohistochemistry services after their initial diagnosis and also those whose immunohistochemistry reports were not found in their case files. Results: Among the 121 women that participated in the study, there were in all 74 (61.2%) had molecular subtyping of their tumour blocks. Up to 45 (37.2%) did not go for molecular subtyping of their tumour blocks while 2 (1.7%) were not sure whether they had or not. Conclusion: It, therefore, depicts that the rate of uptake was found as 61.2% among the participants and there is a need to create more awareness of the importance of molecular subtyping, which necessitates the use of targeted hormone therapy.

Receptor Conversion between Primary Tumors and Distant Metastases in 121 Cases of Metastatic Breast Cancer

The article published in Vol.4 No.2 102-107, 2013 has been withdrawn by the authors for further revision. This paper will be re-submitted to IJCM after the authors revise it.

Estrogen receptor beta suppresses the androgen receptor oncogenic effects in triple-negative breast cancer

Background:Triple-negative breast cancer(TNBC)is an aggressive type of breast cancer associated with poor prognosis and limited treatment options.The androgen receptor(AR)has emerged as a potential therapeutic target for luminal androgen receptor(LAR)TNBC.However,multiple studies have claimed that anti-androgen therapy for AR-positive TNBC only has limited clinical benefits.This study aimed to investigate the role of AR in TNBC and its detailed mechanism.Methods:Immunohistochemistry and TNBC tissue sections were applied to investigate AR and nectin cell adhesion molecule 4(NECTIN4)expression in TNBC tissues.Then,in vitro and in vivo assays were used to explore the function of AR and estrogen receptor beta(ERβ)in TNBC.Chromatin immunoprecipitation sequencing(ChIP-seq),co-immunoprecipitation(co-IP),molecular docking method,and luciferase reporter assay were performed to identify key molecules that affect the function of AR.Results:Based on the TNBC tissue array analysis,we revealed that ERβand AR were positive in 21.92%(32/146)and 24.66%(36/146)of 146 TNBC samples,respectively,and about 13.70%(20/146)of TNBC patients were ERβpositive and AR positive.We further demonstrated the pro-tumoral effects of AR on TNBC cells,however,the oncogenic biology was significantly suppressed when ERβtransfection in LAR TNBC cell lines but not in AR-negative TNBC.Mechanistically,we identified that NECTIN4 promoter–42 bp to–28 bp was an AR response element,and that ERβinteracted with AR thus impeding the AR-mediated NECTIN4 transcription which promoted epithelial–mesenchymal transition in tumor progression.Conclusions:This study suggests that ERβfunctions as a suppressor mediating the effect of AR in TNBC prognosis and cell proliferation.Therefore,our current research facilitates a better understanding of the role and mechanisms of AR in TNBC carcinogenesis.

Inetetamab combined with pyrotinib and oral vinorelbine for patients with human epidermal growth factor receptor 2 positive advanced breast cancer:A single-arm phase 2 clinical trial

Background Human epidermal growth factor receptor 2(HER2)-targeted agents have significantly improved the outcomes of patients with HER2-positive breast cancer;however,a large proportion of patients still develop resistance to trastuzumab.In this study,we investigated the efficacy and safety of inetetamab,another anti-HER2 antibody,combined with pyrotinib and oral vinorelbine in patients with HER2-positive advanced breast cancer so as to provide new ideas for the treatment.Methods In this prospective,single-arm,phase 2 trial,patients with HER2-positive advanced breast cancer with disease progression after trastuzumab were recruited.Patients received a combination of inetetamab(loading dose of 8 mg/kg and subsequent doses of 6 mg/kg intravenously once every 3 weeks),pyrotinib(400 mg orally once daily),and vinorelbine(60 mg/m^(2)orally once weekly)until disease progression or intolerable toxicity.The primary endpoint was progression-free survival(PFS).The secondary endpoints included objective response rate(ORR),overall survival(OS),disease control rate(DCR),and safety.Results Between February 13,2022 and December 25,2022,30 patients were screened and enrolled in this study.The median age of the patients at enrollment was 54 years,12 patients(40.0%)had hormone-receptor-positive disease and 23 patients(76.7%)had visceral metastasis.The median PFS was 8.63 months(95%confidence interval[CI]4.15-13.12 months).The median OS was not reached.The ORR was 53.3%(16/30)and the DCR was 96.7%(29/30).The most common Grade III/IV adverse events were leukopenia(n=5,16.7%),neutropenia(n=4,13.3%),and diarrhea(n=3,10%).No treatment-related serious adverse events or deaths occurred.Conclusions The combination regimen of inetetamab,pyrotinib,and oral vinorelbine showed encouraging efficacy and favorable safety in patients with HER2-positive advanced breast cancer and could be considered as an alternative treatment option for the patients.